The U.S. Supreme Court says it won't take up the case of Minnesota businessman Tom Petters.
In documents made public Tuesday, the nation's highest court denied Petters' request to review his 2009 conviction on charges he orchestrated a $3.65 billion Ponzi scheme.
Petters' attorney Jon Hopeman says he wasn't surprised by the court's decision, which marks the end of the direct appeals process.
Hopeman says Petters is optimistic and doesn't give up easily, and he may pursue other legal remedies.
Petters is serving a 50-year sentence at a federal prison in Leavenworth, Kan. He says he's innocent.
His attorneys had argued that the trial judge barred them from presenting evidence about the criminal past of a key prosecution witness who they say was the scheme's real mastermind.