The prosecution urged the jury to convict, saying the evidence showed that he believed he had a jihad duty to kill as many soldiers as possible.
"There is no doubt, as I said in the beginning, the accused is the shooter," the prosecutor, Col. Steven Henricks, told the jury.
"The only question for you is ... is this a premeditated design to kill?"
For more than 90 minutes, the prosecutor took the jury methodically through the evidence in the case, meticulously piecing together how he says Hasan prepared and planned for the attack.
Prosecutors have maintained that the American-born Muslim underwent a progressive radicalization that led to the massacre at the sprawling central Texas base.
"He did not want to deploy, and he came to believe he had a jihad duty to kill as many soldiers as possible," Henricks told the jury.
Hasan picked the day -- November 5, 2009 -- because it was when the units he was scheduled to deploy with to Afghanistan were scheduled to go through the processing center, he said.
Hasan rested his case without calling a single witness or taking the stand to testify on his own behalf.
His decision not to offer a defense was an anticlimactic end to the trial in which prosecution witnesses, primarily survivors, painted a horrific picture of what unfolded inside a processing center during the attack.
A graphic FBI video during closing arguments
During closing arguments, prosecutors showed a graphic FBI video of the crime scene hours after the rampage, where bodies, blood and bullets still covered the floor.
As the video was shown to the jury, some of the family members of those killed fought back tears.
One woman laid her head on her husband's shoulder, tears pouring down her cheeks, while another woman, a wife of a victim, left the courtroom.
For his part, Hasan watched the video, appearing to pay close attention.
Hasan, who has insisted that the jury not be allowed to consider lesser charges against him, said his attack on soldiers at Fort Hood was not an act of "sudden passion."
There was "adequate provocation" for the attack because the soldiers were going to participate in "an illegal war" in Afghanistan, Hasan told the military judge Wednesday, arguing against the jury being allowed to consider voluntary manslaughter or unpremeditated murder.
Prosecutors argued against the inclusion of lesser charges, saying the attack wasn't carried out in "the heat of sudden passion," and Hasan said he agreed.
The judge ruled that the jurors can consider a lesser charge of unpremeditated murder but not voluntary manslaughter. They can also consider unpremeditated attempted and other lesser charges, she ruled.
Much has been made of Hasan's defense or, as his stand-by attorneys have said, the lack of it. Judge Tara Osborn declined a request by Hasan's attorneys to drop out of the case. The attorneys argued that Hasan was helping the prosecution put him to death.