PORTLAND (AP) — A lawyer trying to overturn a decades-old murder conviction says case files recently returned to police by a retired detective contained critical evidence that was never shown to the defense.

The Portland Press Herald reported (http://bit.ly/2qsZOf2 ) the lawyer, Amy Fairfield, said in court filings that the boxes had been stored in the detective’s attic for an unknown length of time. She says they contained witness statements, police reports and a sketch of another potential suspect. Fairfield says some of that evidence was never turned over to the defense lawyers for Anthony Sanborn, Jr.

Sanborn served 27 years behind bars for the 1989 murder of a childhood girlfriend. The 44-year-old was released in early April on $25,000 bail after a witness recanted her testimony.

The detectives involved in the case have denied hiding evidence.