The sentencing phase also will be Hasan's last chance to tell jurors what he's spent the last four years telling the military, judges and journalists: that the killing of unarmed American soldiers preparing to deploy to Iraq and Afghanistan was necessary to protect Muslim insurgents. Whether he plans to speak, however, remains unclear.
Hasan, an American-born Muslim, has admitted carrying out the attack and showed no reaction when he was found guilty. He is representing himself during his trial, yet he called no witnesses, declined to testify and questioned only three of prosecutors' nearly 90 witnesses before he was convicted.
It remained unclear Monday whether he planned to say anything during the trial's sentencing phase.
The judge, as she has done repeatedly, asked Hasan on Monday if he wanted to continue representing himself. She went through a series of questions that appeared to be aimed at getting on the record that Hasan was adamant about remaining in charge of his own defense.
At the minimum, the 42-year-old Hasan will spend the rest of his life in prison.
Prosecutors want Hasan to join just five other U.S. service members currently on military death row. No American soldier has been executed since 1961. Many military death row inmates have had their sentences overturned on appeal, which are automatic when jurors vote for the death penalty. The U.S. president must eventually approve a military death sentence.
Jurors must be unanimous to sentence him to death.
The Associated Press contributed to this report.