US President Donald Trump has approved the execution by firing squad of Nidal Malik Hasan, the former Army psychiatrist convicted of killing 13 people at Fort Hood in Texas in 2009, according to an announcement by Pentagon spokesman Sean Parnell reported by CNN.

The Pentagon announced the decision on 5 October following a recommendation from Pete Hegseth, CNN reported. An execution would be the US military’s first since 1961, but presidential approval does not end the possibility of further legal challenges.

“Judgement day for Hasan has finally come,” Parnell wrote in a post on X, according to the Associated Press.

Army records establish that the attack took place on 5 November 2009. The 13 people killed included 12 soldiers and one civilian employee, according to an Army account published after the shooting.

Hasan opened fire at a processing centre where troops were undergoing final medical checks before deployment, CNN reported. The Army said civilian police officers confronted him and that one officer was wounded in the exchange.

A military court panel convicted Hasan of 13 counts of premeditated murder and 32 counts of attempted premeditated murder, according to the Army’s official sentencing account.

The panel sentenced him to death on 28 August 2013. It also ordered his dismissal from the service and forfeiture of all pay and allowances.

The Army’s account said relatives of those killed and people who had suffered losses testified during the sentencing proceedings. Hasan did not give a closing argument.

The death sentence required automatic appeals to the Army Court of Criminal Appeals and the United States Court of Appeals for the Armed Forces, the Army explained when it announced the punishment.

The last military execution took place on 13 April 1961, when Private John A. Bennett was executed at Fort Leavenworth in Kansas, according to Army records.

Further civilian court proceedings could still delay Hasan’s execution. CNN, citing the military’s Army Lawyer journal, reported that a prisoner can seek review through a habeas corpus petition challenging the legality of detention, potentially leading to a stay while the courts consider the case.