Monday, November 15, 2010

Likelihood of Innocence: Quantifying reasonable doubt and acceptable collateral damage from false prosecutions

I thought I'd share with readers some interesting stuff I've been reading and thinking about lately from the blogosphere and elsewhere. The missus thinks that, if only for yall's benefit, I should split this up into three posts. She's right, but I've spent too much time editing the damn thing already so I'll just apologize in advance for the length and dive right into it:

The Likelihood of Guilt and Statistical Probability
Via Simple Justice and Eugene Volokh, I found this pair of posts from Steven Landsburg at The Big Questions both provocative and interesting. Go read them both before continuing with this post, since I'll refer to them but won't quote them extensively:
Basically Landsburg offers an example where a small but statistically significant sample (of black and red balls taken from an urn)  points to a particular outcome with a 98% probability of accuracy, arguing  that that level of certainty should be sufficient to secure a conviction "beyond a reasonable doubt."

As a probability game, that's all fine and good. As an analogy for the likelihood of guilt in a given situation, however, perhaps not so much. Even from a statistical perspective, I think the good professor is wrong, at least when you scale up his analysis to a systemic level. He is engaging in what's known among mathematicians as the "base rate fallacy," as evidenced by this example offered up by of all sources, the CIA:
During the Vietnam War, a fighter plane made a non-fatal strafing attack on a US aerial reconnaissance mission at twilight. Both Cambodian and Vietnamese jets operate in the area. You know the following facts:

(a) Specific case information: The US pilot identified the fighter as Cambodian. The pilot's aircraft recognition capabilities were tested under appropriate visibility and flight conditions. When presented with a sample of fighters (half with Vietnamese markings and half with Cambodian) the pilot made correct identifications 80 percent of the time and erred 20 percent of the time.

(b) Base rate data: 85 percent of the jet fighters in that area are Vietnamese; 15 percent are Cambodian.

Question: What is the probability that the fighter was Cambodian rather than Vietnamese?

A common procedure in answering this question is to reason as follows: We know the pilot identified the aircraft as Cambodian. We also know the pilot's identifications are correct 80 percent of the time; therefore, there is an 80 percent probability the fighter was Cambodian. This reasoning appears plausible but is incorrect. It ignores the base rate--that 85 percent of the fighters in that area are Vietnamese. The base rate, or prior probability, is what you can say about any hostile fighter in that area before you learn anything about the specific sighting.

It is actually more likely that the plane was Vietnamese than Cambodian despite the pilot's "probably correct" identification. Readers who are unfamiliar with probabilistic reasoning and do not grasp this point should imagine 100 cases in which the pilot has a similar encounter. Based on paragraph (a), we know that 80 percent or 68 of the 85 Vietnamese aircraft will be correctly identified as Vietnamese, while 20 percent or 17 will be incorrectly identified as Cambodian. Based on paragraph (b), we know that 85 of these encounters will be with Vietnamese aircraft, 15 with Cambodian.

Similarly, 80 percent or 12 of the 15 Cambodian aircraft will be correctly identified as Cambodian, while 20 percent or three will be incorrectly identified as Vietnamese. This makes a total of 71 Vietnamese and 29 Cambodian sightings, of which only 12 of the 29 Cambodian sightings are correct; the other 17 are incorrect sightings of Vietnamese aircraft. Therefore, when the pilot claims the attack was by a Cambodian fighter, the probability that the craft was actually Cambodian is only 12/29ths or 41 percent, despite the fact that the pilot's identifications are correct 80 percent of the time.

This may seem like a mathematical trick, but it is not. The difference stems from the strong prior probability of the pilot observing a Vietnamese aircraft. The difficulty in understanding this arises because untrained intuitive judgment does not incorporate some of the basic statistical principles of probabilistic reasoning.
Bruce Schneier offers a similar example regarding data mining:
Data mining is like searching for a needle in a haystack. There are 900 million credit cards in circulation in the United States. According to the FTC September 2003 Identity Theft Survey Report, about 1% (10 million) cards are stolen and fraudulently used each year. Terrorism is different. There are trillions of connections between people and events -- things that the data mining system will have to "look at" -- and very few plots. This rarity makes even accurate identification systems useless.

Let's look at some numbers. We'll be optimistic. We'll assume the system has a 1 in 100 false positive rate (99% accurate), and a 1 in 1,000 false negative rate (99.9% accurate).

Assume one trillion possible indicators to sift through: that's about ten events -- e-mails, phone calls, purchases, web surfings, whatever -- per person in the U.S. per day. Also assume that 10 of them are actually terrorists plotting.

This unrealistically-accurate system will generate one billion false alarms for every real terrorist plot it uncovers. Every day of every year, the police will have to investigate 27 million potential plots in order to find the one real terrorist plot per month. Raise that false-positive accuracy to an absurd 99.9999% and you're still chasing 2,750 false alarms per day -- but that will inevitably raise your false negatives, and you're going to miss some of those ten real plots.
So if the evaluation of Prof. Landsburg's culpability were an isolated incident, perhaps his analytical assumptions make sense. If the same investigative technique is applied to many people, however, even a 98% level of certainty can produce many false positives, as in these examples.

There's another mitigating wildcard to examine before we declare this one piece of datum sufficient for a conviction: Landsburg's assumptions included the statement, "While you weren’t looking, I reached into one of these urns and randomly drew out a dozen balls…4 of them were red and 8 were black." But what if that's a lie? What if while you weren't looking, Prof. Landsburg went into the left-hand urn and counted out a precise, predetermined number of red and black balls for his own purposes? Provocatively, Landsburg goes so far as to declare that "If I were on trial for the crime of drawing from the right urn, I hope this evidence would be strong enough to convict me," without even insisting that the balls in each urn be counted to ensure the theft really took place!

If taking balls from the right urn is a crime, why should we take the word of a criminal that the balls were indeed chosen randomly? :) In all seriousness, actually creating a law against taking balls from the right urn creates an incentive for the ball-taker to lie. For that matter, if someone wanted to make it falsely appear that the right urn was the source of balls that were really handpicked from the left, they would successfully fool others 98% of the time if they made sure their "random" pickings mirrored a right-urn pattern. In the world of statistical parlor games governed by hard-and-fast assumptions and rational decisions, those percentages make sense. In a world where 25% of DNA exonerations involved false confessions or guilty pleas, not so much.

Landsburg says "I hope this evidence would be strong enough to convict me," but depending on the jurisdiction that might be overly hopeful. In Texas state court, it may. In military courts martial, though, as well as in federal court, a confession must be independently corroborated by other evidence. The assumption that the balls were taken from an urn randomly comes from a stand-alone confession for which there is no corroboration. And of course, as one of Landsburg's commenters noted, in the real world one seldom would know the exact distribution of balls in each urn: In other words, much evidence in criminal cases includes elements of uncertainty which are merely assumed away in this hypothetical. Moreover, witnesses sometimes embellish or lie in ways that aren't always anticipated by game theory.

'n Guilty Men'
Relatedly, via Landsburg's discussion and Eugene Volokh's tout, I also discovered this wonderful and humorous 1997 law review article, "n Guilty Men," by Alexader Volokh (brother of Eugene), which traces the variations throughout history of the sentiment, most famously stated by William Blackstone, that it's better for ten guilty men to go free than to punish an innocent one. He begins by pointing out that there's not universal agreement on whether ten is the right number:
But why ten?  Other eminent legal authorities through the ages have put their weight behind other numbers.  "One" has appeared on Geraldo. 7  "It's better for four guilty men to go free than one innocent man to be imprisoned," says basketball coach George Raveling. 8  But "it's better to turn five guilty men loose than it is to convict one innocent man," according to ex-Mississippi executioner and roadside fruit stand operator Thomas Berry Bruce, who ought to know. 9  "It is better to let nine guilty men free than to convict one innocent man," counters lawyer Bruce Rosen from Madison, Wisconsin. 10  Justice Benjamin Cardozo certainly believed in five for execution, 11 and allegedly favored ten for imprisonment, 12 which is a bit counterintuitive.  Benjamin Franklin thought "that it is better [one hundred] guilty Persons should escape than that one innocent Person should suffer." 13  Mario Puzo's Don Clericuzio heard about letting a hundred guilty men go free and, "struck almost dumb by the beauty of the concept . . . became an ardent patriot." 14  Denver radio talk show host Mike Rosen claims to have heard it argued "in the abstract" that it's better that 1000 guilty men go free than one innocent man be imprisoned, and comments, "Well, we get our wish." 15

       Or, perhaps, it may be merely "a few," 16 "some," 17 "several," 18 "many" (and particularly more than eight), 19 "a considerable amount," 20 or even "a goodly number." 21  Not all commentators weigh acquitting the guilty against the conviction of one innocent man.  A Missouri district court said in 1877 that it was "better that some guilty ones should escape than that many innocent persons should be subjected to the expense and disgrace attendant upon being arrested upon a criminal charge." 22  And in Judge Henry J. Friendly's opinion, "Most Americans would allow a considerable number of guilty persons to go free than to convict any appreciable number of innocent men." 23  It is unclear whether "considerable" is greater or less than "appreciable." 24
       n guilty men, then.  The travels and metamorphoses of n through all lands and eras are the stuff that epic miniseries are made of.  n is the father of criminal law.  This is its story. 
Excellent stuff, huh? Volokh sees the roots of these mathematical calculations over the relative value of innocent men in the story of Abraham haggling with God over the fate of the sinful city Sodom, the scriptural account of which is the epigraph to his article:
And Abraham drew near and said, Wilt thou also destroy the righteous with the wicked?  Peradventure there be fifty righteous within the city: wilt thou also destroy and not spare the place for the fifty righteous that are therein?  That be far from thee to do after this manner, to slay the righteous with the wicked: and that the righteous should be as the wicked, that be far from thee: Shall not the Judge of all the earth do right?  And the Lord said, If I find in Sodom fifty righteous within the city, then I will spare all the place for their sakes.

       And Abraham answered and said, Behold now, I have taken upon me to speak unto the Lord, which am but dust and ashes: Peradventure there shall lack five of the fifty righteous: wilt thou destroy all the city for lack of five?  And he said, If I find there forty and five, I will not destroy it.  And he spake unto him yet again, and said, Peradventure there shall be forty found there.  And he said, I will not do it for forty's sake.  And he said unto him, Oh let not the Lord be angry, and I will speak: Peradventure there shall thirty be found there.  And he said, I will not do it, if I find thirty there.  And he said, Behold now, I have taken upon me to speak unto the Lord: Peradventure there shall be twenty found there.  And he said, I will not destroy it for twenty's sake.

       And he said, Oh let not the Lord be angry, and I will speak yet but this once: Peradventure ten shall be found there.  And he said, I will not destroy it for ten's sake. 
From this Volokh sensibly takes it that God's bottom line n for guilty people who may be freed for the sake of an innocent person would be n = (P-10)/10 where P = the population of Sodom. So, if Sodom was a town of 3000 people, by this logic God would countenance letting 299 guilty men go free for the sake of a single innocent [(3000 - 10)/10].

Volokh also cites Talmudic interpretations from the middle ages of Exodus 23:7 which came to the conclusion that, for purposes of execution, it was better to let 1,000 guilty men go free rather than convict an innocent one!  (To jibe with Volokh's calculations vis a vis Abraham's bargain, Sodom's population would have had to have been 10,010.) I'm really just providing a taste, though, the whole thing is a must-read and IMO flat-out hysterical. (My favorite part is the send up of Blackstone's divinity and immortality.)

Acceptable Error Rates?
These discussions are dancing around the question of how many innocent people are falsely accused and convicted? And assuming the answer is greater than zero, what error rate is tolerable? Over the past couple of years this blog has compiled available estimates of actual innocence rates among prison inmates based on various methodologies and datasets, with results ranging on the low end from .75% to 3.3% on the high end. However you slice it, that's a not-insignificant false-positive rate. At a rate of .75%, we would assume there are 1,200 actually innocent people locked up in Texas prisons right now; at 3.3%, the total exceeds 5,000. (The rate among probationers is likely a little higher because of the incentive innocent people have to take a deal to avoid incarceration.)

Perhaps, given these data, Blackstone's 10-1 false-negative to false-positive ratio was always a little too stingy; perhaps Ben Franklin's n=100 is a better standard. I fail to understand why, if manufacturing companies can adopt "six sigma" error standards where "in which 99.99966% of the products manufactured are statistically expected to be free of defects (3.4 defects per million)," that the criminal justice system couldn't shoot for at least a four-sigma error rate (99.38% accurate). Criminal justice is a field where relatively high error rates are routinely tolerated in high-stakes circumstances.

These debates hone in on key, fundamental questions: What error rate is tolerable in the justice system - both false positives and false negatives - and how may those errors be reduced? How many innocent people is it acceptable to punish in pursuit of punishing the guilty, or is that ever justified? How much evidence is sufficient to convict and what constitutes reasonable doubt? I don't know the answer to all these questions, but they're interesting topics to think about and discuss.


Anonymous said...

When it comes to human life and liberty, we're not playing with balls out of a jar. I think there can be no statistical measure of reasonable doubt.

I would venture that Abraham did not go below ten in his haggling with the Almighty because he feared there would be none. Paul, not Abraham but of his seed, said, "There is none righteous, no, not one." I believe, as a matter of faith, that God would have spared Sodom for the sake of one righteous. Lot, his wife and his daughters, escaped Sodom. We know what happened to Lot's wife. Read the rest of the story for the sordid account of Lot and his ddaughters.

Rev. Charles

Anonymous said...

All good questions to ask, Grits. Conversely, if the demand for success or certainty is set too high in the criminal justice system, there will likely be a statistically significant number of guilty defendants who get off, or go unpunished. Take the O.J. Simpson case for example. A large portion of our population in this country was convinced "beyond a reasonable doubt," that O.J. was guilty. They view the acquittal in that case as a "failure" of the system. I know there were other dynamics at play in that case, but you get the point. If a significant number of guilty people begin to go free (and, more importantly, begin to reoffend) do you think the public will understand that they originally walked because we were only 90% convinced of their guilt? As opposed to 98.7%?

Don said...

5:11 Yes. We have always understood that guilty people walk because of a small, yet "reasonable" doubt. That's the way the system was meant to be. What percent of guilty people do you suppose don't ever even get arrested?

shg said...

Thanks for posting Sasha Volokh's article, perhaps the only law review article I've ever wanted to read twice. It shouuld be spread as far as possible. Even to Texas.

Anonymous said...

Don, we also understand that a certain number of innocent people may be convicted under the "beyond a reasonable doubt" standard. That's also the way the system is meant to be. If that were not so, we would make the standard "absolute certainty" or 100 percent certainty. I the question that Grits seems to be getting at here concerns what the public's comfort level is for guilty people going unpunished vis a vis innocents being wrongly convicted. My guess is that this comfort level goes up or down in direct proportion to how fearful of crime the public is at any given point in time.

Hook Em Horns said...

I would wager that the collateral damage from judicial malfeasance in Texas is substantial. The statistics back this up. Therefore, acceptable collateral damage in Texas is, or has been, quite high.

Hook Em Horns said...

Anonymous said...
Don, we also understand that a certain number of innocent people may be convicted under the "beyond a reasonable doubt" standard. That's also the way the system is meant to be. If that were not so, we would make the standard "absolute certainty" or 100 percent certainty. I the question that Grits seems to be getting at here concerns what the public's comfort level is for guilty people going unpunished vis a vis innocents being wrongly convicted. My guess is that this comfort level goes up or down in direct proportion to how fearful of crime the public is at any given point in time.

11/15/2010 07:13:00 PM

That may be the intent of Grit's question and for the folks on this board, it's worthy of hearing there response. Make no mistake though, the "sheeple" of Texas HAVE NO CLUE HOW THE JUSTICE SYSTEM WORKS! And, THEY DON'T CARE! It's easier to sit back and let others worry about it and buy the "stupid on crime" bullshit we are fed from birth.

The "sheeple" aren't ready for the truth and, to be honest, probably cannot handle it.

I have said it before and I will repeat it here. Those closest to the system KNOW DAMN GOOD AND WELL what the problems are and where they lie. There is a huge disconnect between those of us involved in the law and those watching it on the 6:00 news.

When the District Attorneys in the states biggest counties have or are establishing post-conviction relief units while our Governor says "the system works," the level of denial is thorough, the damage is catastrophic.

Unknown said...

I think a fair amount of your post is misleading, although I think the point you are trying to make is completely fair.

First of all, you state that "Even from a statistical perspective, I think the good professor is wrong, at least when you scale up his analysis to a systemic level"

What you have done is not scale it up to a "systemic level", but instead have just changed the type of problem you are looking at.

In his example, the probability that he picks one urn or the other is related to the probability that he would pull out 8 black and 4 red. As in, if he picked one earn, his chances of picking 8 black and 4 red is different than if he picked the other.

In your Vietnamese/Cambodian problem, the pilot identifies correctly 80% of the time, and wrong 20% of the time, whether or not the fighter is Vietnamese or Cambodian.

One could argue that your situation is one that you are more likely to find in real cases, but I would have to think about that more deeply before I decided one way or the other. Regardless, it is not the case that if you "systematized" the probabilistic formula he applied that it would become less correct. Landsburg has certainly not committed a base rate fallacy. To me, the main point, regardless, is whether 98% certainty is beyond a reasonable doubt. However, one could construe him to be saying that evidence can often easily be quantified like in his problem, but I doubt it. He is certainly not arguing that when the defendant is more likely innocent than guilty that is enough to convict.

Unknown said...

Your comparison of the 98% knowledge that someone committed a crime to 1% false positive rate and .1% false negative rate when searching for 10 terrorists out of one trillion indicators is also misleading.

Prof. Landsburg method would produce a pretty clear number of false positives - not over 2%. Assuming we were 98% sure for every criminal we convicted, that means 2% of the people we convicted would be innocent. However, assuming that we convicted everyone who we were 98% sure or greater, then it would be less than 2%.

The situation of looking for 10 terrorists in a morass of different people is an entirely different probabilistic situation than whether to convict someone when you are 98% sure that they committed the crime. The base assumption of the data mining problem is that there is only 10 people you want out of billions of people. The base assumption of Landsburg's problem is that you have one person in front of you and you are 98% certain that he is guilty. Applying the 98% over and over again will not produce over 2% false positives.

However, your point that Landsburg tries to throw in - that some how you know that he picked the urn by a flip of a fair coin (he adds this in the comments) - does not exist in the real world, and thus your never going to have this 98% certainty in evidence, is completely valid in my view.

Anyway, thanks for the interesting post. I'm no probability maven, so feel free to point out if I made any mistakes. It took me quite awhile to figure out how to calculate the 98% probability in the original post.

Gritsforbreakfast said...

Thanks Aaron, for your thoughtful comments. Fwiw, this post was just an effort for me to think through the issues; if it's "misleading" it may just be because I haven't fully wrapped my head around the subject. Like you, I'm no probability maven.

However, for the reasons you cite in your second comment, I dispute "The base assumption of Landsburg's problem ... that you have one person in front of you and you are 98% certain that he is guilty." If that's the assumption it's not true. You couldn't convict beyond a reasonable doubt without making other assumptions about where the balls came from (one of the urns) and how (chosen randomly). All we can say is there is a 98% chance the balls came from the right urn IF assumptions of randomness, etc., are true.

Does that mean 98% of people in possession of 4 red balls and 8 black ones are thieves? No, only if they a) took the balls from a forbidden urn and b) chose randomly. Scale up Landsburg's method and you'll falsely accuse lots of red-and-black ball owners for whom the assumptions are false. Schneier's example shows that when accurate techniques are scaled up, they can produce far more false positives than the facial percentages would lead you to guess.

Consider: DNA is virtually 100% accurate, but someone can be falsely accused if their DNA is located at a crime scene because they left it there earlier that day, etc.. The fact that one element of the investigation has a low error rate doesn't mean whenever that technique is used it always identifies the guilty person.

Finally, I do believe the situations I described are more common in real cases, and the reason is my examples don't rely on assuming away the messy parts of reality but observing how investigative techniques are actually used, which is a lot less clean and efficient than in Landsburg's hypothetical.

Anonymous said...

Aaron and 5:11 have interesting concerns but their concerns actually illustrate the point of the post. There are other factors that aren't always considered by jurors that cause them to miss an underlying concern that would easily cause someone to have a reasonable doubt and vote not guilty. Just as was the case in the Cambodian Vietnam actual probability of error rate. So it becomes obvious when, as a defense lawyer, or anyone else who follows this issues that things like problems with eyewitness id get overlooked and jurors put all their eggs in one basket. Besides a statistical analysis the average juror makes up their mind early on and is emotionally invested in their decision. It becomes hard to get them to believe the problems with eyewitness id, or fingerprints or dogs. (Hopefully these discussions make it easier for some). So it becomes hard not to believe the marbles weren't jacked with. The worse heinous the case the more jurors like 5:11 want to focus on we can't just let this guy go. The point of different folks giving 1 in 5, 10, 100, or 1000 is not to figure out what the number should be but to say a couple of things. 1) We would be foolish to convict everyone brought into the system; and 2) Because there is an overwhelming consensus that we don't want to convict and innocent person and we have to let a number of guilty go free, we have to take reasonable doubt very seriously and not let our emotion get in the way of identifying reasonable doubt. The statistics in this article weren't made to analyze 98% but only to say that you may think someone is guilty beyond a reasonable doubt, but you had better have made that decision not just with the evidence that was presented that was obvious, but also the evidence that was not presented and how that may also lead to reasonable doubt. Maybe not doing a proper scene analysis with fingerprints, hair samples and DNA is a reasonable doubt. One old prosecutor circumstantial evidence analogy is - If you went to bed tonight and the ground was clear and the next morning you look out the window and see snow. Even though you didn't see it snow you know that it did snow. Maybe that does not answer the question as a counter to that could be but we don't know what dark cloud the snow came from. This oversimplifies the point but the first part sounds real good until you think about it from another concern or perspective. That is how I went from supporting the death penalty in law school to seeing all the problems with the system, especially the number of innocents convicted, to now opposing the death penalty. Excellent article Grits. I hope everyone catches these concerns and internalizes them. The sad thing is that many would have to see everything in the battlefield and in articles like this to really get it.

Anonymous said...

I wonder which jar this "ball" came out of:

Samaritan death suspect had fled halfway house
Man had several warrants issued since his parole last year

A man accused of gunning down a Good Samaritan who intervened during an purse snatching last week had been on the run since October when he fled from a Houston halfway house.

Anthony Ray Ferrell, 39, was arrested Sunday and charged with capital murder in the slaying of Sam Irick, 24, at a Chevron station in the Meyerland area. He is in the Harris County jail without bail.

Ferrell has a Harris County criminal record going back almost 20 years. In 1993, he was sentenced to 20 years for armed robbery. He was paroled in 2009 but was identified last June as a parole absconder.

State officials filed at least two more arrest warrants for other parole violations. In October, Ferrell was again taken into custody and sent to a state-contracted halfway house in the 10900 block of Beaumont Highway.

On Monday, the details on what led officials to file the parole warrants were not available.

Ferrell's decision to flee the halfway house in October led to the final parole violation warrant against him. He remained at large until Houston police arrested him in Irick's death.

"This crime was tragically senseless but utterly preventable," said crime victims advocate Andy Kahan.

Services for Irick were Monday.

Irick's mother said she heard about Ferrell's arrest when her husband stopped by the crime scene to thank the gas station clerk who assisted her son.

"It was such a relief to have him arrested before the funeral," Randi Wood said. "The more time passes, you worry and wonder if he's going to be caught. It makes the whole thing more bearable."

Lawrence Wood, Randi Wood's husband, said he wasn't surprised to learn of Ferrell's extensive criminal background.

"I look forward to seeing him get the maximum punishment for what he did," Wood said.

Amberly Wait, the woman whom Irick defended at the gas station, attended Monday's funeral with her family.

"It was a very emotional day for us at the funeral," said her husband, Jeb Wait. "It was the first time we were able to meet the family and it brought everything together for us."

Wait said his wife is doing well and their family is relieved that the prime suspect in the fatal shooting is off the street.

Randi Wood was presented with an American flag at her son's funeral by Congressman Al Green.

"It was such an honor," Wood said.

Don said...

Scott: You probably drew out the only 4 or 5 people out of thousands that read your blog that could even discuss this halfway intelligently. I had a couple of statistics courses in college, but I'm not about to try to wrap my head around this stuff, primarily because I think it's comparing apples and oranges, anyway. It seems to try to quantify variables that are not quantifiable, such as guilt and innocence, as you would material "balls".

Anonymous said...

For some reason the idea of quantifying evidence to determine reasonable doubt in the American justice system brought to mind the question of, "How many angels can dance on the head of a pin", for whatever that is worth.

freekory said...

I have a story that need to be told it involes arlington police swat team shooting a man durning a raid , and falsely charging him with atte3mted capital muder on a pease officer with 2million dollar bond , then the police report doesnt even say the shot him , non of this was ever on the news please someone help me there is so much more to this story please this will be a big police scandle

Gritsforbreakfast said...

9:06, what exactly is your point?

10:33, that phrase popped into my head while thinking about this as well.

Anonymous said...

I think you missed most of the point of the article, Grits. Landsburg's point, it seems to me, is that what may appear to be a reasonable doubt to the untrained eye may actually be closer to a near-certainty, e.g., the students who sais that the chance of his having drawn from the statistically-likely jar were only 75%, when in fact it is 98%. I think he is attempting to tell us that what we may view as a "reasonable" doubt may in fact be a mere possibility. At least in the realm of statistics, people may often view an outcome as being much more likely than it actually is mathematically.

I also have to agree with him that a system that results in even a 2% error rate of false convictions is one that most of use could certainly live with. I know that many people will cry "What if you were one of the 2%? Huh? Then how would you feel?" Bad, for sure. But how much better would I feel knowing that 50 guilty criminals go free in order to make sure that one innocent is not harmed? How many innocents will be harmed by those 50 unpunished criminals? Do we really prefer to create a situation that maximizes the number of victims in order to minimize the number of innocents convicted? Or do we draw the line closer to where Landsburg puts it?

Gritsforbreakfast said...

2:33 - I didn't miss that point, I disputed it because of Landsburg's myopic focus on the quantifiable, arguing out that his limiting assumptions have no analogy in the justice system.

If you can live with 2% false convictions, from the available estimates, IMO that's about what we've got - maybe a tad higher. So if 1 out of every 50 people convicted is innocent, then there are about 3,100 actually innocent people sitting in Texas prisons (assuming ~155K incarcerated) and thousands more on probation and parole. If that's okay with you, great - end of discussion. Given the volume processed through the justice system, though, that's a lot of folks.

gravyrug said...

I think that statistics be damned when we're talking about convicting someone of a crime. Reasonable doubt should be taken on a case-by-case basis, with ALL the evidence taken into account.

Anonymous said...

9:06, I get your point loud and clear. Sam Irick was not a statistic or a ball out of some jar. He was a living, breathing, really good person who wound up taking a bullet and giving his life to protect an innocent woman who was in harm's way. People like Grits, and Barry Scheck, always like to gloss over tragedies like this because it's such a compellingly overwhelming distraction to their "touchy, feely, hug-a-thug" drivel that they cannot even begin to formulate a reasonably articulate reponse.

Anthony Ray Ferrel is a turd. A worthless POS that deserves to die for what he did. This crime occurred on video, Grits. The whole freaking thing! There will be NO doubt as to his guilt. This will be a case of absolute certain. No tainted evidence. No faulty eyewitness ID's. No coerced confessions. Just a turd with a rap sheet a mile long who killed a young hero under circumstances where the death penalty is clearly called for. I genuinely hope Lykos steps up to the plate and does what's right on this case. And I hope some Harris County jury tells those Innocence Project folks what they can do with their death penalty moratorium.

Gritsforbreakfast said...

4:35, since it's so clear to you, perhaps you can clarify: If there's no doubt as to this fellow's guilt, how does the case play into a discussion over the scope of reasonable doubt? How is it relevant to this discussion? Or would you and 9:06 just prefer to change the topic to something else? That's what it seems like.

Anonymous said...

I can't speak for 9:06, Grits, but my guess is that the reason he (or she) posted that Houston Chronicle article in this thread is that he figured it's the only way it would ever get mentioned on your blog. We've heard about Willingham, Claude Jones, etc., on this blog lately ad nauseum. I think Sam Irick's murder, and the circumstances under which it happened, just reinforces why the vast majority of people in Texas appreciate that we have the death penalty available, and actually use it. I know that you're not as rabidly anti-death penalty as some of these liberal kooks who frequently post on hear. It would be refreshing though if you would occasionally give some mention to these types of heinous crimes which seem to just cry out for the ultimate punishment.

Hook Em Horns said...

Anonymous said:

"But how much better would I feel knowing that 50 guilty criminals go free in order to make sure that one innocent is not harmed?"

Well, there are more than 50 running free in Texas because the idiots in the judicial system and law enforcement strung up the wrong person. do you feel?

Gritsforbreakfast said...

So 5:20, you really did just want to change the subject! You'd simply prefer if I spent all my time talking about "heinous crimes which seem to just cry out for the ultimate punishment," as though such commentary is underrepresented out in the world.

Unfortunately for you, I spend little time debating the death penalty or other Culture War topics on Grits. There are lots of other blogs focused on those issues if that's what you're looking for. For that matter, the Houston Chronicle has 200X Grits circulation, so don't feel like word won't get out if I don't happen to mention a particular story.

Anonymous said...

Wow, someone has evidently struck a nerve by questioning Grits' lack of objectivity. Dude, don't get so defensive!

Gritsforbreakfast said...

6:31, I don't even believe in "objectivity."

Nobody struck a nerve, they're just trying to drag the comment string off topic. I'm used to it.

Anonymous said...

The amount of tolerance we should have is zero tolerance.

The problem is that, as with any human system, there will always be errors, either wrongful convictions or wrongful acquittals.

That is the purpose, the beauty, and the flaw of "reasonable doubt" as a standard. Although jurors may make mistakes, judges oversee that. And where judges may make mistakes, governors and executive agencies are given the power to remedy that.

Sometimes the system fails, sure, but what else can we do?

Gritsforbreakfast said...

9:23 said, "as with any human system, there will always be errors," so "what else can we do?"

I'd respond that it's not enough to say any system has errors. The task is to constantly try to solve them wherever possible.

When someone dies in a hospital they hold a collective "M&M conference (Morbidity and Mortality) in which all the doctors analyze what went wrong, ask questions, then suggest improvements either for the individual doctor, the hospital's need for equipment, training, staffing, etc. that are intended to constantly improve their success rate, recognizing all the while that errors happen in any system and sometimes people will die.

So you can use that observation to justify complacency, or you can accept it as the ongoing challenge that it is and fix the problems that are immediately in front of you, recognizing that down the line more may yet arise.