The Trump administration has approved a plan to execute former Army Maj. Nidal Hasan — who killed 13 people in a 2009 shooting at Fort Hood — by firing squad, chief Pentagon spokesman Sean Parnell said late Monday.

Parnell said on social media the plan to use an Army firing squad was recommended by Defense Secretary Pete Hegseth and approved by President Trump.

“The Secretary of the Army will set the time and place of the execution. Judgement day for Hasan has finally come,” Parnell wrote.

CBS News has reached out to Hasan’s attorney for comment.

A former Army psychiatrist, Hasan was convicted of murdering 13 people and injuring more than 30 in a 2013 court-martial. Hasan acknowledged at trial that he was responsible for the shooting, claiming he opened fire on fellow members of the Army in an attempt to protect Islamic insurgents from U.S. military forces. He was sentenced to death.

Hasan’s case could mark the military’s first execution of an American service member since 1961, when a soldier was hanged for raping and attempting to murder an 11-year-old girl.

It would also mark a rare use of a firing squad. The method was used in South Carolina three times last year, marking the first firing squad executions since 2010. 

The federal government typically uses lethal injection for civilian death penalty cases. Earlier this year, the Justice Department said federal officials should consider other methods, including firing squads, electrocution and lethal gas.

The decision by Hegseth comes after a lengthy appeals process for Hasan. He chose to represent himself at trial, and in an unusual course of events, he clashed with his own court-appointed standby attorneys, who worried that Hasan was intentionally seeking the death penalty. 

Hasan asked the Supreme Court to review his case in 2024, arguing the judge violated his right to a public trial by clearing the public from the courtroom before discussing some of his issues with the attorneys. The high court declined to take up the issue last year.