The case goes back to a grisly quadruple homicide in Detroit in 2007.
Police interrogated 14-year-old Davontae Sanford, who says he was coerced into giving a false confession.
Former Detroit police commander James Tolbert was one of the cops who questioned Sanford. He testified in court that Sanford was able to draw a crime scene sketch for police of where the murders took place.
But later, Tolbert admitted to police that he actually drew most of the sketch.
Still, Wayne County Prosecutor Kym Worthy announced late Tuesday there's insufficient evidence to charge Tolbert with perjury. Her office says even if Tolbert changed his statements about evidence, it’s really hard to actually prove perjury, because you have to prove that somebody intentionally lied under oath.