After 11 days of testimony, the trial will now proceed to closing arguments, WFAA-TV, Dallas, reported.
Hasan, 42, is representing himself against charges he killed 13 people and injured 32 others.
Hasan had originally planned to call as his only defense witness Dr. Lewis Rambo, an expert on religious conversion from San Francisco Theological Seminary. After he changed his mind Tuesday, Judge Col. Tara Osborn still required Hasan to meet with him Tuesday night.
If Hasan had testified, he would have been subject to cross-examination by prosecutors.
Richard Rosen, a professor at the Texas Tech Center for Military Law, said Hasan could wait until sentencing to speak. If he testifies under oath, Hasan still would be subject to questioning by Army lawyers. He could give an unsworn statement but it could carry less weight with the trial panel.
Former U.S. Attorney General Ramsey Clark said he was talking to Hasan about representing him during sentencing.
He has said he walked into the medical deployment center on the Killeen, Texas, base on Nov. 5, 2009, to kill as many soldiers as he could as part of a jihad to protect Muslims and Taliban leaders from troops heading to Afghanistan.
The mass shooting was the worst shooting at a U.S. military base.
Hasan began the court-martial Aug. 7 by telling the jury of 13 senior Army officers he was the gunman.
"The evidence will clearly show that I am the shooter," he said.
If convicted, the Army psychiatrist could face the death penalty or life in prison without parole.
"If you choose to testify, it is your choice and your choice solely," Osborn told Hasan Tuesday.
"If you do testify, you have to ask yourself questions. ... You can't simply give a statement. It has to be in a question-and-answer format."
Hasan has no legal training, and his former military attorneys, who Osborn has ordered to remain as legal advisers, have said he doesn't take their advice because he wants a death sentence.
Among the final prosecution witnesses was a civilian who testified he photographed Hasan during the shooting.
Asked if he recognized the man in the courtroom, Bennett pointed at Hasan, identifying him as "the bearded individual." Hasan has refused to shave, citing his religious beliefs.
The last prosecution witness was a doctor who worked with Hasan at Fort Hood's medical center in the weeks before the attack.
Dr. Tonya Kozminski testified Hasan told her before the shooting there would be consequences if the Army deployed him to Afghanistan. He earlier said he considered himself a conscientious objector on religious grounds.
"The last thing he said to me was, 'They will pay,'" Kozminski testified.
The unit with which he was to deploy was ordered to report for processing Nov. 5, 2009.