CCTV proponents should abandon claims that surveillance cameras reduce crime

John Honovich, a consultant on video surveillance and biometrics, says in a meta-analysis of recent studies of CCTV effectiveness that the industry needs to change its marketing pitch. Particularly it must stop promising the public CCTV can reduce crime, primarily because virtually all the research on public CCTV use shows that it fails to reduce crime. As a result, Honovich makes the following suggestion for CCTV proponents:

Recommendation: Abandon emphasis on general crime reduction

Proponents of public CCTV systems should abandon the emphasis and claim that CCTV systems can reduce crime generally. Even if proponents ignore the fact that studies demonstrate this, clinging to this claim only creates greater debate and dissension.

By abandoning this claim, it will heal some of the major discord and allow all parties to focus on better uses of CCTV. Given the vastly improved quality of today's CCTV systems at greatly reduced prices, this should be reasonable to accomplish.

Honovich says CCTVs more important use is in solving crimes, citing the much-different reasons usually articulated for private sector adoption of cameras. So far, he says:

the focus of all quantitative analysis has been on reducing crime.

This is the mirror opposite of the private sector. In the private sector, the overwhelming majority of CCTV systems are justified by their use in solving crime. It is investigations where most private businesses find value and return in their CCTV systems. For businesses, only a very small percentage of CCTV cameras are ever even watched. The systems pay for themselves by periodically being able to identify or prove a criminal activity.

This indicates a failure of expectations for public CCTV systems. In the private sector, when CCTV effectiveness is discussion, the assumption is usually that CCTV is used for investigations. By contrast, the focus on public CCTV effectiveness being determined on reducing crime sets a dangerous expectation that is difficult to achieve and likely to create dissatisfaction within the community.

The problem seems to be the fault of the original advocates of these systems, rather than a deficiency of the testers. The academics and researchers performing these tests were reacting to the expectations that the proponents of these systems made originally.

So Honovich thinks public surveillance proponents have merely framed the problem incorrectly, that the studies showing negligible effects on crime mean that proponents must change their pitch. But if we're to judge CCTV by its effectiveness, what are we to make of news from the UK that in London, the most surveilled city on the planet, surveillance footage is used to help solve only 3% of street robberies?

A British detective writing in 2006 declared "CCTV viewing occupies a dis-proportionate amount of police time with very little tangible result," and that "identification is rarely assisted by CCTV" in police investigations. Typically, he said, the "footage will show that some kind of offence has taken place. It is more than useless for the purposes of finding out who did it."

Video surveillance works better when focused on low-traffic areas and high-value targets, which is how the private sector uses it - to protect specific assets. For example, cameras would have been a useful security measure in recent thefts from southeast Texas police property rooms. Parking garages are another area with low-traffic but high-value targets where studies show cameras provide added protection.

But general public surveillance? Not so much. According to the UK Guardian:

Use of CCTV images for court evidence has so far been very poor, according to Detective Chief Inspector Mick Neville, the officer in charge of the Metropolitan police unit. "CCTV was originally seen as a preventative measure," Neville told the Security Document World Conference in London. "Billions of pounds has been spent on kit, but no thought has gone into how the police are going to use the images and how they will be used in court. It's been an utter fiasco: only 3% of crimes were solved by CCTV. There's no fear of CCTV. Why don't people fear it? [They think] the cameras are not working."

IMO Honovich overstates the case when he says that "Widespread consensus exists that CCTV is effective in reducing premeditative/property crime." I don't think there's evidence that CCTV in public places reduces property crime. Used for specific high-value targets or in areas with limited access (e.g., the car park or police evidence room examples), there's a consensus cameras provide a significant added layer of security, but that's a more limited claim.

Even with Honovich's focus on solving crime instead of reducing it, the cost-benefit analysis for public camera surveillance hardly supports its use by police. Citing how much cheaper cameras have become and reduced costs for transmission systems, Honovich suggests that proponents of CCTV adopt a new metric to promote their product: Cost per camera. He writes:

While most studies cited general cost numbers, the cost per camera was largely ignored. The most frequently cited number is the amount the UK home office has spent on CCTV (500 million pounds). However, only the 2005 UK Home Office study actually broke down the cost per camera. Since the studies were focused on determining if the crime rate was reduced, this element is understandable. Nevertheless, communities could save significant money and improve effectiveness by more carefully tracking the cost per camera.

Understanding the cost per camera is important to recognize changes in technology and to identify waste. The 2005 UK Home Office report indicated that cost per camera ranged from $7,000 pounds to $33,000 pounds for cameras installed in the late 1990s and early 2000s.

This is a useful but IMO incomplete suggestion. A better metric would be "cost per crime solved using cameras." Simply measuring (or reducing) the cost per camera alone tells us very little about whether those cameras are making us more secure.

The studies Honovich cites have usefully demonstrated that, despite massive public investment in the UK in particular, surveillance cameras do not reduce crime on the front end. We also know that in a small number of criminal cases, they help solve them on the back end, though they're more likely to do so when cameras are focused on high-value targets and/or low traffic areas. Even so, cameras are easily defeated by low-tech means like hats, scarves and sunglasses, and at best provide only a small additional increment of safety when they're deployed.

The question now becomes: Is that increment worth the massive costs associated with installing and monitoring public CCTV surveillance? So far, most of the evidence says "no," but I welcome the introduction of new metrics to measure the question.

Hat tip to Bruce Schneier.

UPDATE: Noam Biale of the national ACLU emails to ask if I'd post a link to the organization's recent white paper on surveillance camera effectiveness, so here you go (pdf).