At the time of his death, Maj. Brent Taylor was part of a 3-year-old multinational program to train Afghan troops, police forces and security units in the ongoing struggle against the Taliban.

Taylor, 39, a Utah National Guard officer who was mayor of North Ogden, died in an apparent insider attack during a training exercise Nov. 3.

He was one of nearly 8,500 U.S. service members working under the framework of the NATO-directed Resolute Support Mission in the war-scarred nation.

According to information provided by the U.S. Army, Resolute Support fields more than 16,000 troops from 39 countries to help drive the Afghan government’s four-year security roadmap, which aims to increase effectiveness and accountability of national security forces and institutions.

A Resolute Support document said trainers focus on leadership development and combat capabilities, emphasizing Afghan special operations forces and the air force.

“Unity of command and fighting corruption” also are chief training goals, the document said.

Taylor was working in one of five regional training hub command sites, his in the capital of Kabul. Units his group advised included the Afghan army’s 111th Capital Division, Kabul City Police, Afghan National Civil Order Police and the Afghan Border Police.

Afghan troops are being trained to “conduct intelligence driven, multi-pillar offensive operations, secure strategic terrain, and provide multi-layered security to … coalition bases and Afghan government infrastructure,” the document said.

At a NATO summit last summer, ministers “committed to sustaining the mission until conditions indicate a change is appropriate.”

Taylor’s death remains under investigation, U.S. Army Maj. Bariki Mallya, a spokesman at NATO’s Resolute Support Headquarters, said Wednesday.

NATO and U.S. Department of Defense press releases in early November said the attacker shot Taylor with small arms fire and was then killed by other Afghan troops.

Another American service member was wounded in the attack but was treated and returned to duty, NATO said.

Mallya said no new information is available. He said he did not know how long the investigation will take.

Once such an investigation is complete, “Leadership reviews it, decides what if any changes need to be made, take appropriate action, and we go forward from there,” Mallya said.

Jennie Taylor, Brent Taylor’s widow, said she doesn’t know much about the circumstances of her husband’s death. The only information she has are the details provided on Nov. 3 when military authorities first informed her of the incident that killed her husband.

“They said he had been killed in a ruck march and that he was shot. I know that he went on a ruck march every Saturday,” she said.

Ruck marches, she said, are training exercises in which participants wear all their gear, which can weigh up to 80 pounds.

Other than that, she hasn’t gotten any official information, though officials have told her they’ll provide more details pending completion of the probe into the matter.

Rahmat Gul, Associated Press

According to Department of Defense data, Taylor is one of 59 U.S. service members killed during Operation Freedom’s Sentinel, which began Jan. 1, 2015.

In Operation Enduring Freedom, from Oct. 7, 2001, through Dec. 31, 2014, 2,216 U.S. service members were killed.