A man serving life in prison for the 2009 killings of his wife and their two young sons in southwestern Illinois is asking for his convictions to be tossed on claims that decisions by the trial judge prejudiced jurors against him.

An attorney for Christopher Coleman argues in a petition with the Mount Vernon-based 5th District Appellate Court that jurors were wrongly allowed to see videos and photographs of Coleman and his lover.

Coleman's appeal also argues that prosecutors didn't sufficiently prove their case.

Thirty-seven-year-old Coleman was convicted of strangling his wife and sons at the Coleman's Columbia home in 2009.

He is serving his life sentences at a prison outside of Illinois.

The state appellate prosecutor's office has until March 31 to file a response to the appeal.