The Consequences of Mistakenly Acquiring a DNA Sample for a Law Enforcement Databank

Should a state be permitted to convict a rapist who is caught because his DNA is placed in a database in violation of the state's DNA databank statute? In People v. Robinson, 224 P.3d 55 (Cal. 2010), the California Supreme Court upheld the sexual assault convictions of a man whose DNA was taken by correctional officials who mistakenly thought that the state’s DNA database statute applied to the misdemeanor for which he was convicted. This search thus violated the state law but not the U.S. Constitution, which permits DNA sampling from those convicted of some (if not all) misdemeanor offenses. Because the state database law did not prescribe the exclusion of evidence at trial as a remedy, the California court could have upheld the convictions without discussing the scope of the Fourth Amendment exclusionary rule.

Yet, the Robinson court described a second ground for its action -- the "good faith" exception to the Fourth Amendment exclusionary rule announced in United States v. Leon, 468 U.S. 897 (1984). The facts of Leon were compelling. Why exclude reliable physical evidence from trial when it was not the constable who blundered, but “a detached and neutral magistrate” who misjudged whether probable cause was present and issued a search warrant? Later cases applied the exception for “good faith” mistakes to other forms of police reliance on facts or other information supplied by officials. Just this month, in United States v. Davis, No. 09–11328 (U.S. June 16, 2011), the Court refused to apply the exclusionary rule to a search that conformed to circuit court precedent at the time, even though the Supreme Court devised a different rule two years later. More to the point, in Herring v. United States, 555 U. S. 135 (2009), a police officer, pursuing a grudge against a suspect, arrested and searched him and his truck on the basis of a false and negligent report from a clerk in another county of an outstanding arrest warrant. The Court held that this "attenuated negligence" did not warrant the application of the exclusionary rule.

In an essay published last month, I argue that the Robinson court exceeded the boundaries of the good-faith exception by applying it to a nonattenuated negligent mistake. The essay, "Unraveling the Exclusionary Rule: From Leon to Herring to Robinson—And Back?," 58 UCLA L. Rev. Disc. 207 (2011), is at http://uclalawreview.org/?p=1719.

Cross-posted from the Double Helix Law blog.