A mishap at the Westchester District Attorney?s office could mean a convicted killer may go free.

A federal judge will soon decide if Anthony DiSimone?s 2001 conviction will be overturned in the murder of 21-year-old Louis Balancio. DiSimone, of Yonkers, is serving 25 years to life for fatally stabbing Balancio outside a Yonkers bar in 1994. Police say DiSimone was a prime suspect and a member of a street gang with ties to the mob. He was on the lam for six years before he eventually turned himself into police. He was later convicted.

Now DiSimone?s conviction is in jeopardy after prosecutors admitted in court that they did not turn over all the evidence in the case to defense attorneys. DiSimone?s attorneys say the evidence might have proven their client innocent. They are filing papers to overturn the conviction. Prosecutors have until mid-January to file their motions, then the judge will make a decision.