ATLANTA (AP) — A jury is considering whether to sentence a federal inmate to death for killing his cellmate at the U.S. Penitentiary in Atlanta.

The jury began deliberating Brian Richardson’s fate on Tuesday after prosecutors and defense attorneys delivered closing arguments.

He was convicted last month of the July 2007 killing of Steven Obara, who prosecutors say was targeted because he was a child molester.

Prosecutors say it was a case of cold-blooded murder by a man with a history of violence behind bars. Defense lawyers maintain that Richardson was mentally ill at the time but has since stabilized after receiving proper medication.

Richardson could be the first person sentenced to death in federal court this year.