October 14, 2009, Muncie, Indiana (AP / The Republic / Star Press) - The father of an Indiana National Guardsman who fatally shot himself inside a movie theater said Tuesday that the families of service members returning home from war need to closely watch them for signs of stress.

Army Specialist Jacob Sexton, 21, showed no signs of being suicidal before shooting himself in the head, the guardsman's father, Jeffrey Sexton of Farmland, said.

"We just need to watch these boys and the girls coming back home. Something's just not right. Too much is happening," Jeffrey Sexton told The Associated Press in a telephone interview.

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Muncie police said Jacob Sexton had argued with theater employees on Monday night over having to show identification to see the R-rated horror comedy "Zombieland." Twenty minutes into the film, a friend handed Sexton a 9 mm handgun, at the guardsman's request, and he then shot himself in the head, police said.

Sgt. Mike Engle told The Star Press that witnesses told officers that an employee at the Muncie theater asked Sexton for ID and that he replied that he had killed 18 people while in the military. Engle said it appeared Sexton and some of his companions had been drinking.

About eight other people were in the theater at the time of the shooting. No one else was hurt, police said.

The guardsman's father said the shooting wasn't an accident. He said Sexton's younger brothers, also at the theater, said the guardsman told a friend to duck, and when the friend hesitated, Sexton pushed the friend's head down before the shooting.

Jeffrey Sexton said he and his wife, Barbara, had not noticed any signs of stress.

"This all came as a complete surprise to us. He'd been happy since the day he joined. He was planning on re-enlisting," Jeffrey Sexton said.

Indiana National Guard officials said Jacob Sexton was home on a 15-day leave and was scheduled to return to Afghanistan at the beginning of next week.

He was serving with the Indiana National Guard's Alpha Company, 2nd Battalion, 151st Infantry Regiment. The unit responds to attacks on military installations or convoys near the Kabul area, said Lt. Col. Deedra Thombleson, a guard spokeswoman.

Sexton had spent three months in Iraq in 2006-07, she said.

First Sgt. Steven Bishop said Sexton was a "great kid" who volunteered to go to Afghanistan. He let other guard members in the unit select their leave dates before choosing his so that everyone else could get their first pick, Bishop said.

"He was always smiling - always joking," Bishop said. "He was always making the best out of any situation and never complained. It's really a shock for all of us. This would have been the last thing in the world we would have expected from him."