Army Recruiter Murder-Suicide: Michelle Miller's father says teen tried to help her alleged killer, Adam Arndt

(CBS/AP) ROCKVILLE, Md. - Community members gathered at a Maryland high school Tuesday night to honor the senior who was killed in a murder-suicide by a troubled U.S. Army recruiter she was trying to help, CBS DC reports.

Pictures: Teen Army recruit slain in murder-suicide

Hundreds of people met on Rockville High School's football field to release balloons in memory of 17-year-old Michelle Miller, who was found dead Monday morning in the apartment of Staff Sgt. Adam Arndt.

Police believe 31-year-old Arndt fatally shot Michelle, who was signed up to enter the Army Reserves after graduating this spring, before killing himself. They said a handgun was found at the home.

Michelle had ambitions to become a therapist, helping military personnel struggling after returning from combat, according to her lacrosse coach Caitlin Ulmer.

Michelle's lacrosse teammates honored her Tuesday by wearing pink T-shirts reading "#1 on the FIELD. #1 in our HEARTS," CBS DC reports.

"I have a feeling our building is going to be one great big memorial to Michelle Miller," said Rockville High School Principal Dr. Debra Munk.

Michelle's father, Kevin Miller, said his daughter was a "little smitten" with Arndt, a nine-year Army veteran who served overseas in Korea, Germany and Turkey. He said his daughter was excited to join the military and planned to use it to finance her college education.

"She had her life taken away from her on one fell swoop," he said.

Arndt was assigned to coordinate Michelle's entry into the Reserves after graduation. He was detailed in January 2011 to a recruiting office in Columbia, Md. His duties included visiting schools, but Army recruiters are barred from fraternizing with recruits, said Kathleen Welker, a spokeswoman for the U.S. Army Recruiting Command. This restriction includes dating, inviting recruits to their homes or having any kind of personal relationship that would place undue influence on a recruit.

Kevin Miller said his daughter told him she was going to help somebody in her platoon that was suicidal around 9:15 p.m. Sunday. Miller said he was against the idea, but his daughter was adamant she would be fine and promised to text him the address when she arrived.

The father says he received a vague text message from her about the address, but she did not respond to subsequent attempts to contact her.

Miller called police around midnight. In the morning, one of his daughter's friends gave him details about where she might be. He drove to the location, saw Michelle's car and called police again shortly before 9 a.m. after no one answered the door.

Officers discovered the bodies after forcing entry into the home.

"That generous spirit may have cost her her life," Kevin Miller told CBS affiliate WUSA.

Grief counselors were at Rockville High School on Tuesday as students coped with the loss of their classmate, CBS DC reports.

More on Crimesider
April 9, 2013 - Staff Sgt. Adam Arndt, Army recruiter, allegedly killed 17-year-old recruit, then self