In 1992, a criminal justice study found that police perjury was actually occurring 20% of the time that defendants were claiming that it was occurring. Similar studies went so far as to find that there is a tacit agreement among police officers that it's okay to lie about how evidence was seized to keep dangerous criminals off the street. There's even a word for it: testilying.
The Exclusionary Rule as an Incentive for Officers to Perjure Themselves?
Yesterday's WSJ argued that the exclusionary rule might be to blame for false testimony by officers. For those of you who are more than a couple years away from that crim pro course, the exclusionary rule is the rule that requires state courts to throw out evidence illegally seized.
Empirical evidence backs up the idea that the exclusionary rule could be to blame for the false testimony. Apparently, after the Supreme Court decided Mapp v. Ohio (the case which declared evidence obtained by illegal searches inadmissible) in 1961, the number of cases where suspects mysteriously dropped bags of drugs on the ground sharply increased.
2009 Decision Chips Away at the Exclusionary Rule
On January 14, 2009, the SCOTUS released its opinion in Herring v. U.S. ruling (5-4) that the exclusionary rule does not apply from an unconstitutional search which resulted from of "isolated and attenuated" police negligence. (In Herring, it was a record keeping error.) The WSJ notes that narrowing the exclusionary rule will decrease officers' incentive to testily. However, civil rights advocates argue that narrowing the exclusionary rule provides a more dangerous incentive for officers to act on hunches without fear that resulting evidence will be inadmissible.