PERU — The wife of a Maine soldier killed by an Afghan police officer says he had misgivings about training and arming Afghans.

Chelsea McLain of Peru says Pvt. Buddy McLain expressed his concern a week before his death. She said he told her he was going on a dangerous mission. She told the Sun Journal, “He didn’t think it was right to train these people and give them guns.”

Buddy McLain was a cavalry scout with the 101st Airborne Division. He deployed from Fort Campbell, Ky., on Aug. 24, 2010, which was his son Owen’s first birthday.

He was one of six soldiers killed Monday when the border policeman turned his gun on his trainers.

Maj. Gen. John Campbell said today that the lone gunman shot five soldiers from behind before turning and shooting a sixth. Campbell said U.S. soldiers immediately killed the gunman.

The shootings occurred in Nangarhar province near the Pakistan border.

The Taliban claimed responsibility, saying the officer had enlisted as a sleeper agent to have an opportunity to kill foreigners.

The Pentagon identified the other soldiers as Sgt. Barry E. Jarvis of Tell City, Ind.; Pfc. Jacob A. Gassen of Beaver Dam, Wis.; Spec. Matthew W. Ramsey of Quartz Hill, Calif.; Pvt. Austin G. Staggs of Senoia, Ga., and Staff Sgt. Curtis A. Oakes of Athens, Ohio.