Nidal Hasan, the US Army psychiatrist who shot dead 13 people at Texas Army base Fort Hood, has declined to make a statement as jurors begin considering his sentence.
Major Nidal Hasan, 42, faces the death penalty after being found guilty of the attack at Fort Hood Army base in 2009.
He is defending himself but has stayed largely silent throughout his trial.
During the sentencing phase on Tuesday, Nidal Hasan rested his case without offering any witnesses or providing evidence in favor of a life sentence.
The former military psychiatrist had previously tried to admit multiple murder charges, but military rules ban guilty pleas in death penalty cases.
Nidal Hasan was convicted of 13 counts of pre-meditated murder and 32 counts of attempted murder on Friday.
He said he opened fire on unarmed US soldiers, killing 13 and wounding many more, to protect Taliban insurgents in Afghanistan.
The military jury, which reached a unanimous verdict in seven hours, began the penalty phase of the trial on Monday.
Nidal Hasan has declined to make a statement as jurors begin considering his sentence
For the 13-member panel to recommend that the judge sentence Nidal Hasan to death, it must come to a unanimous agreement. If the panel members do not agree, he will face a life sentence in prison.
The US military has not executed a service member since 1961. There are five inmates on the US military’s death row at Fort Leavenworth, Kansas, all at various stages of the appeals process.
Among the last barriers to military execution is authorization from the president.
Nidal Hasan, a Virginia-born Muslim, rested his case shortly after family members of those killed, along with soldiers wounded in the rampage, gave emotional testimonies about their lives since the attack on 5 November 2009.
His court-appointed legal advisers tried to step in on his behalf.
But military judge Colonel Tara Osborn denied their request, saying Major Nidal Hasan had the constitutional right to represent himself.
“It is my free and voluntary decision,” he told her.
Closing arguments are scheduled for Wednesday, but it is unclear whether jurors will hear from Nidal Hasan again, the Associated Press reports.
His court-appointed lawyers previously told the judge they believed he sought execution in a bid for martyrdom.
Nidal Hasan opened fire at a medical facility on the Fort Hood base where soldiers were being evaluated before deploying overseas.
Prosecutors said he had prepared carefully for the attack for weeks and fired a total of 146 bullets.
The shooting spree ended when Nidal Hasan was shot by a civilian police officer. He was paralyzed from the waist down from the wound and now uses a wheelchair.
Cleveland kidnapper Ariel Castro appeared in court today to accept a plea deal under which he will serve a life sentence plus 1,000 years for the kidnap and rape of Amanda Berry, Michelle Knight and Gina DeJesus.
Ariel Castro, 53, was said to have agreed to the deal – after initially pleading not guilty to all 977 counts against him – to spare him the death penalty. His previous not guilty pleas were withdrawn.
Under the offer, Ariel Castro will spend the rest of his life behind bars without the possibility of parole, meaning he will die in prison.
It also means his three victims Amanda Berry, Michelle Knight and Gina DeJesus will not have to testify about their more than ten-year ordeal in front of a jury.
Speaking in court today, Ariel Castro said: “I said I was willing to work with the FBI and I would tell them everything.”
The judge asked him if he understood that he would die in prison and there would never be a possibility he would be released from prison.
Ariel Castro replied: “I do understand that and I said because of the s** crimes I knew I would have the book thrown at me.
“There are some things I do not comprehend because of my s**ual problems throughout the years. But I trust my lawyers and I understand my rights and the sentence.”
Ariel Castro appeared in court to accept a plea deal under which he will serve a life sentence
Offering some form of an explanation for his despicable crimes, Ariel Castro said: “I was a victim as a child and it just kept going.”
The judge cut him off and told him to save his story for his sentencing hearing.
Prosecutors said if evidence of additional crimes came to light, Ariel Castro could still be indicted on future charges that included the death penalty.
Ariel Castro’s lawyers have said for weeks that they would consider an agreement under which the former Cleveland school bus driver would plead guilty to some charges in return for his life.
He has been charged with 977 counts including kidnapping and repeated rape. He has also been charged with murder under a fetal homicide law for allegedly forcing one of the women to miscarry.
Gina DeJesus, 23, Michelle Knight, 32, and Amanda Berry, 27 were freed from Ariel Castro’s home in a rundown area of Cleveland in May.
The house will be torn down, it was revealed this week.
Also freed was a six-year-old girl who, according to DNA evidence, was fathered by Ariel Castro with Amanda Berry during her captivity.
A grand jury on July 17 added 648 charges to a previous indictment against Ariel Castro and an $8 million bond was put in place.
The indictment against Ariel Castro alleges he repeatedly restrained the women, sometimes chaining them to a pole in a basement, to a bedroom heater or inside a van.
It says one of the women tried to escape and he assaulted her with a vacuum cord around her neck.