Maj. Nidal Malik Hasan will be executed by firing squad at Fort Hood, Texas, on Dec. 3, for fatally shooting 13 people and wounding 32 in 2009 at the same base, the Army said in a statement on Wednesday.

The rampage was the deadliest mass shooting on an American military installation.

President Trump approved the execution earlier this week. The execution could still be derailed, but if it is carried out, Major Hasan will be the first person to be executed through the military justice system since a soldier was hanged in 1961.

The last U.S. service member executed by firing squad, however, was Pvt. Edward Donald Slovik, who was convicted of twice deserting his unit in combat and was put to death in France on Jan. 31, 1945.

Major Hasan is currently being held at the military death row prison in Fort Leavenworth, Kan.

Major Hasan, who is paralyzed from the waist down after being shot four times by law enforcement officers during his attack, was convicted by courts-martial of 45 counts of premeditated murder and attempted premeditated murder on Aug. 23, 2013.

He was sentenced to death five days later.

Sean Parnell, a Defense Department spokesman, posted on social media on Monday that “judgement day for Hasan has finally come.”

According to a 2023 Army regulation on procedures for military executions, “all lawful and feasible methods available” for executing prisoners will be presented to the Army secretary for consideration, without elaborating on what those methods are.

The acting secretary of the Army, Adam R. Telle, chose death by firing squad for Major Hasan.

The Army regulation states that condemned prisoners will be executed no sooner than 60 days and no later than 150 days after presidential approval of the sentence.

Major Hasan will be shot to death at Fort Hood at 1 p.m. Central time on Dec. 3, just 63 days after Mr. Trump approved the action.

The condemned prisoner’s attorney, Jonathan F. Potter, declined to comment via phone on Wednesday.

Whether Major Hasan, who uses a wheelchair, will be shot sitting down or strapped upright to face the firing squad is unclear.

The 2023 regulations also state that “a minimum” of two news media representatives will be selected to witness the execution.

On Nov. 5, 2009, Major Hasan, an Army psychiatrist stationed at Fort Hood, took a personal handgun onto the base grounds and opened fire.

Major Hasan said that he carried out the attack, which occurred at the height of the post-9/11 fight against terrorism, to wage jihad for what he called the illegal and immoral wars in Afghanistan and Iraq.

Chris Cameron contributed reporting.