A judge is refusing to let a young Detroit man withdraw his guilty plea to four slayings, despite a confession from a hit man who's in prison for eight other murders.

The decision is a major blow to Davontae Sanford, who says he admitted to the fatal shootings at age 14 to please police. He subsequently pleaded guilty to second-degree murder but has been fighting for more than three years to have the plea thrown out.

There's no dispute that hit man Vincent Smothers told police that he committed the 2007 Runyon Street homicides. But Wayne County Judge Brian Sullivan said Tuesday that Smothers' confession doesn't mean Sanford should be exonerated.

Smothers is willing to testify for Sanford, but the judge says no. Smothers now is 19.  

Attorneys for Sanford said the case will now head to the Court of Appeals.