The jury will return Thursday to consider the case of Brian Richardson, who was convicted last month of the July 2007 killing of Steven Obara.
Prosecutors say Richardson is a cold-blooded killer who targeted the 60-year-old Obara after learning he was a child molester. They also told the jury he has a long history of violence behind bars that included attacking a guard and other inmates.
Defense lawyers argue 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 since June.