Criminal justice reform turns to list of problem officers

In this June 13, 2019 photo, Sean Ellis poses for a photo outside the Suffolk County Superior Court House in Boston. During the 22 years he spent in prison after being convicted of killing a Boston police detective, Ellis believed there was something suspicious about the officers who led the murder investigation. He just couldn’t prove it. It would take years of digging and scores of public information requests from his attorneys to uncover evidence that several officers investigating the 1993 murder case were involved in criminal activity, information that wasn’t shared with the defense.