Samuel Gross. the Michigan law professor who maintains the National Registry of Exonerations, reports in Update 2012 that 178 exonerations were added to the registry during the year. Among hopeful signs is that police and prosecutors are becoming more cooperative, more willing to acknowledge error. A prime example the registry reports is David Ranta who was "convicted in 1991 of the attempted robbery of a diamond courier and the murder of a rabbi in Brooklyn, New York. The Kings County District Attorney's Office Conviction Integrity Unit re-investigated the case and determined that police had coached witness identifications, and that authorities had provided favors and made deals with numerous witnesses who lied to implicate Ranta. The District Attorney's Office dismissed the case on March 21, 2013."