It's a few months old, but here's a pretty crazy case of prosecutorial malfeasance from Santa Clara County, California.
San Jose Det. Matthew Christian created a fake DNA report signed by a fictitious lab technician to use as a prop while interrogating a man under investigation for sex crimes against a developmentally disabled neighbor. Police are allowed to lie to suspects in an effort to extract information or confessions, so Christian hadn't violated any laws in actually creating the report.
The problem is that the fake report somehow made its way into Deputy District Attorney Jaime Stringfield's file, along with a real report stating that no DNA could be found on the blanket in question. At a preliminary hearing, Stringfield then proceeded to question the Det. Christian about the fake report. Christian obliged with false testimony.
"This blanket that you seized, did you submit it to the crime lab for analysis?" she asked.
"Yes," Christian said.
"Are you aware of any results?" she asked.
"Yes. There was semen found on the blanket," Christian said.
Superior Court Judge Gilbert T. Brown ordered Kerkeles to stand trial. Stringfield listed Roberts, the fake analyst, among her trial witnesses.
Stringfield blamed the defense attorney for not pointing out the discrepancy in the two reports. But according to the article, defense attorneys twice asked for more information on the reports. Stringfield declined their requests. The defense finally made a third request, this time for the resume of the fictitious lab technician who signed the fake report, at which time Det. Christian remembered that he had made the whole thing up.
An "internal committee" of prosecutors later concluded that Christian's fake report, false testimony, and memory lapse, and Stringfield's failure to notice the fake report, failure to notice the real report, and failure to distinguish between the two—were all "honest mistakes."