In a long overdue move, Gov. Jerry Brown of California just signed into law SB 687, which bans judges and juries from convicting defendants based solely on the uncorroborated testimony of jailhouse informants. From the bill itself:
This bill would additionally provide that a judge or jury may not enter a judgment of conviction upon a criminal defendant, find a special circumstance true, or use a fact in aggravation based solely on the uncorroborated testimony of an in-custody informant, as defined. The bill would provide that corroboration shall not be deemed sufficient if it merely shows the commission of the offense, the special circumstance, or the circumstance in aggravation. The bill would provide that the corroboration of an in-custody informant shall not be provided by the testimony of another in-custody informant.
This is a major step forward in the fight against unreliable and wrongful convictions. Jailhouse snitch testimony has obvious problems, which have been chronicled here before, and in fact, this bill is identical to one passed by the California legislature in 2008, only to be subsequently vetoed by the Governator. Despite opposition from some prosecutors offices, Gov. Brown made this requirement the law of California and for good reason. This survey [PDF] from the Center for Wrongful Convictions at Northwestern Law School found that fully 48% of wrongful convictions were brought about by jailhouse testimony. The Innocence Project states that 15% of DNA exonerations were in cases of convictions that featured snitch testimony. Here’s a Pew Trust report [PDF] on the problems with this kind of testimony.
Surprisingly, California now becomes only the 18th state to enforce this kind of prohibition. Most other states take a half-hearted approach, like Connecticut, providing only for a “special” jury instruction warning juries to consider this kind of testimony skeptically. From the model jury instructions:
Generally, the court should not instruct the jury on the credibility of a particular witness, but the Supreme Court has recognized three exceptions: the complaining witness, an accomplice, and an informant. See State v. Patterson, 276 Conn. 452, 470 (2005); State v. Ortiz, 252 Conn. 533, 561-62 (2000).
The exception for informant testimony was first recognized in State v. Patterson, 276 Conn. 452 (2005). “Because the testimony of an informant who expects to receive a benefit from the state in exchange for his or her cooperation is no less suspect than the testimony of an accomplice who expects leniency from the state, we conclude that the defendant was entitled to an instruction substantially in accord with the one that he had sought.” Id., 470. Though originally limited, in Patterson, to informants who had actually been promised a benefit in return for his or her testimony, in State v. Arroyo, 292 Conn. 558 (2009), the Court expanded it to any informant. “[T]he trial court should give a special credibility instruction to the jury whenever [jailhouse informant] testimony is given, regardless of whether the informant has received an express promise of a benefit.” Id., 569.
If the testimony is so inherently unreliable, then courts and juries should be prohibited from relying solely on such testimony to convict people. But that, I suppose, is a matter for the legislature and not the courts.