When does the adversarial system commence?

Even most non-lawyers know that the United States uses an a adversarial system of justice in both civil and criminal law. Recently in Rothgery v. Gillespie County, the US Supreme Court heard oral arguments regarding the question of precisely when the investigative function of police ends and the adversarial legal system commences - is it upon indictment, at the bail hearing, upon arrest?

Doc Berman has used the phrase "comfortable legal fictions" to describe high-minded but empirically erroneous theories undergirding the legal system, and one such fiction is the idea that, under an "adversarial" system, investigation and prosecution of crimes are separate functions. Police are "fact finders," under this theory, while the adversarial system as it's usually understood commences when formal court proceedings begin.

To judge by the oral arguments, Justices on SCOTUS appear inclined to decide that the adversarial functions of the criminal justice system commence sometime after arrest, either at the initial bail proceedings or perhaps weeks later upon indictment. The case should be decided later this year, so we'll get their official answer then.

But an excellent new book I'm reading right now, "Police Interrogations and American Justice" by Richard Leo, makes a strong case that the adversarial system really begins well before the point in the process discussed in Rothgery. "Once police have decided to interrogate a suspect," he argues, "they have, in effect, crossed the line that separates police work from prosecutorial work. They have aligned themselves with the prosecution in orientation and goal; their function at this point becomes more prosecutorial than investigative."

Leo says that "American police interrogators are adversarial in the sense that they are committed to the goal of incriminating the accused in order to assist the state in its prosecution"; they are "highly partisan, strategic, and goal directed."

Why is that a bad idea? "If police act as partisans or become committed to a prosecutorial agenda in their investigations, it is not just prosecutors whose perceptions and decisions may be distorted. Defense lawyers, judges and juries may also end up relying on biased, incomplete, erroneous, or one-sided information in forming judgments, making decisions, and dispensing justice."

Leo describes how police are trained and encouraged to use "fraud" and "deception" to elicit incriminating statements, an analysis even prosecutors would find hard to deny. Indeed, "unlike courtroom lawyers, police interrogators do not represent themselves as the suspect's adversary. Instead, in what must be one of the deepest ironies in American criminal justice, they portray themselves as the suspect's advocate."

Strong stuff, and Leo provides the evidence and concrete scholarship to back it up. As Anne Reed over at Deliberations declared, "There are briefs to be written out of this book. If enough of them win, the reforms Leo proposes in his final chapter might begin to take hold."

At a minimum, the portion of the book I've read so far tells me the debate over when the adversarial system commences will likely not be finally decided in Rothgery, save to preserve the comfortable legal fiction that police activities in the interrogation room are not aligned with the prosecution.