An Eagan principal who let a parent shoot balloons with a BB gun in the school gym called his decision "unwise" on Monday after questions about the incident led to a school district investigation.

The balloon-popping took place after a ceremony held the evening of Dec. 8 for students graduating from a drug-awareness program at Red Pine Elementary. The kids got certificates, cake and helium balloons -- some of which floated up to the ceiling. To get the balloons down, Principal Gary Anger let a parent volunteer bring a BB gun from home to pop them while a few people finished cleaning up the gym.

The BB gun troubled some adults in the school district, where students caught with weapons have been expelled. After Star Tribune reporters learned of the incident and started asking questions on Monday, officials in the Rosemount-Apple Valley-Eagan District said they were investigating it.

"It's obviously not something that we condone," said district spokesman Tony Taschner.

When it comes to firearms, however, the rules are different for principals than they are for students.

Secondary students who show up with weapons -- even lookalikes -- are recommended for expulsion in the district, with the school board deciding penalties on a case-by-case basis. In the spring of 2008, two high school students were kicked out for the rest of the school year after they bought souvenir swords during a school trip to Britain.

However, district policy does allow firearms on school property in certain situations. Peace officers and color guards can have them, for example, and other people can carry firearms if a principal gives them written permission.

Even so, Anger said Monday that he made a mistake. "As always, the safety of your children is my greatest concern," he wrote in an e-mail to parents at the school. "It is my hope that my decision did not send a mixed message regarding the importance of safety at Red Pine Elementary."

According to the principal, the BB gun first came up on the afternoon of Dec. 8, when a student's father asked if he could bring the gun to shoot balloons that had escaped while he and other volunteers were decorating the gym for the school's D.A.R.E. graduation ceremony.

"I said, 'No, you can't, there's kids around,'" Anger said. But when the parent asked if he could pop the balloons after the ceremony, the principal said that would be OK. "I didn't see any harm in that, but in retrospect, it was probably a dumb thing to do."

The parent volunteer, whom Anger declined to name, attended with his child and then left the school to get the BB gun, the principal said. He returned earlier than expected, Anger said, showing up with the weapon while a few people were still in the gym.

With Anger standing by, the parent took aim and began shooting at the balloons.

Anger would not say whether any students were in the gym at the time, but said "at no point was anyone in danger." An Eagan police officer who worked with the D.A.R.E. students had already left the building, he said.

The district has not put Anger on administrative leave, although Taschner did not rule out disciplinary action as a result of the investigation.

News of the BB gun met with mixed reaction from parents.

"I'm not super excited about it. Our district has a pretty strict policy with weapons," said Scott Haisting, who has a son in fifth grade at Red Pine. At the same time, "I just love our elementary school, and I love our principal and he usually has excellent judgment. I'm kind of torn."

Other parents said they were upset about the media's interest in the story, not the BB gun.

"[The students have] worked so hard," said Julie Andersen, who was also at the ceremony. "I hate for something like this to take away from the energy and the hard work that these kids and this police officer have done this fall."

Sarah Lemagie • 952-882-9016