By Paul Kurtz

PHILADELPHIA (CBS) — Dozens more convicted criminals will be set free as a result of the actions of a  corrupt Philadelphia police officer.

READ MORE: Meat Loaf, 'Bat Out of Hell' Rock Superstar, Dies At 74

Judge Sheila Woods-Skipper has dismissed 59 more cases related to investigations by officer Jeffrey Walker, the former narcotics officer who pleaded guilty to corruption and related crimes.

That brings the total number of vacated cases related to Walker to 160.    Fifty-eight other cases were upheld by the judge.

READ MORE: 3 Sharon Hill Police Officers Fired After Being Charged In Shooting Death Of 8-Year-Old Fanta Bility

Robin Godfrey, a spokeswoman for district attorney Seth Williams says today’s ruling closes the book, for the most part, on Walker.

“It’s very disappointing to our office to have to agree to vacate convictions that we believe were valid,” she noted.

The DA has been reviewing Walker’s cases since he was indicted in May 2013 for shaking down a drug suspect.  He’s been cooperating with prosecutors ever since, providing information that led to the arrest of six other narcotics cops over the summer.

MORE NEWS: Investigation Underway After Man Shot In Southeast Philadelphia