The death of a retired Marine major general is under investigation after his body was found at the training base he once commanded

Law enforcement is investigating the death of retired Maj. Gen. William Mullen after his body was found at the Marine Corps' largest training base.

• Law enforcement is investigating the death of a retired US Marine Corps major general in California.
• Maj. Gen. William Mullen's body was found Saturday at the Marine Corps Air Ground Combat Center.
• Mullen served for 34 years before retiring in 2020 as head of the Training and Education Command.

Law enforcement is investigating the death of a retired major general whose body was found Saturday at Marine Corps Air Ground Combat Center Twentynine Palms, California, officials confirmed to Military.com.

Retired Maj. Gen. William Mullen, 59, a former Marine Corps officer with multiple deployments to Iraq, was found on the installation at Building 1651 over the weekend, according to San Bernardino County Coroner records.

A spokesperson for the Naval Criminal Investigative Service told Military.com on Tuesday that the military law enforcement entity is investigating the death.

"I can confirm that NCIS is conducting a thorough investigation into the death of retired Maj. Gen. William Mullen, as we do in response to any non-combat, medically unattended fatalities involving Navy and USMC equities, service members, and affiliated civilian personnel," said Darwin Lam, a spokesperson for the agency.

When asked, NCIS did not disclose the manner of Mullen's death.

"Out of respect for the investigative process, NCIS will not comment further while the investigation remains ongoing," Lam said.

Gloria Huerta, a spokesperson for the San Bernardino County Sheriff's Department, told Military.com on Tuesday that the local coroner's office responded to Mullen's death at around 3 p.m. Saturday afternoon.

She said that the autopsy is ongoing and that the sheriff's department is not directly involved in the investigation with NCIS, only that its coroner's office is "handling the cause and manner of death."

Mullen assumed command of Twentynine Palms in 2016 as a brigadier general. Commissioned as an artillery officer, he served with the Marine Corps in a bevy of roles for 34 years, to include Marine Aide to the President of the United States, according to his official biography. Before retiring in 2020, he served as the commanding general of Training and Education Command.

"Maj. Gen. Mullen's dedicated service to our nation and the Marine Corps will always be remembered," Maj. Gen. Thomas Savage, head of the Marine Air Ground Task Force Training Command, said in a statement shared Tuesday with Military.com. "Our thoughts and prayers are with his loved ones."

The Los Angeles Times first reported that NCIS is investigating the former general's death. Twentynine Palms is the largest Marine Corps base in the world, according to the installation's website.

In May, Gunnery Sgt. Robert McDonald, a Marine at the installation, was killed when an 18-year-old fired a weapon into McDonald's vehicle while he was sitting with his dog at a park just 10 miles south of Twentynine Palms.