National Registry of Exonerations 2012 report.
The number of cases in which police and prosecutors helped exonerate innocent defendants dramatically increased in 2012.
Law enforcement authorities initiated or cooperated in more than half of the known exonerations last year: 34 out of 63 cases. It was the first time law enforcement contributed to the majority of exonerations in a year, according to the NRE.
The previous high was 2008, when law enforcement officials assisted in 22 of 57 known exonerations. Of the 1,050 exonerations since 1989 that the NRE has identified, prosecutors and police have cooperated in about 30 percent.
The NRE is a joint project of the University of Michigan Law School and the Center on Wrongful Convictions at Northwestern University School of Law. When it was launched in May 2012, the registry listed 891 cases.
Researchers attribute the increase in law enforcement participation to several developments, including “changes in state laws that facilitate post-conviction DNA testing, the emergence of Conviction Integrity Units in several large prosecutorial offices, and, perhaps, a change in how law enforcement officers view the possibility of false convictions at trial.”
While law enforcement was more likely in 2012 to help exonerate innocent defendants, researchers noted that official cooperation is still rare for highly aggravated or publicized cases.
http://www.law.umich.edu/special/exoneration/Documents/NRE2012UPDATE4_1_13_FINAL.pdf