SCOTTSDALE, Ariz. -- It wasn't a real kidnapping and shooting. But police in Scottsdale, Ariz., said what they were doing is a crime.

Three 15-year-old high school students were charged with disorderly conduct in connection with simulating a shooting and a kidnapping. A neighbor saw what was happening and called 911.

It turns out the girls were working on a video project for a criminology class.

A 75-year-old woman who was videotaping them has been arrested on suspicion of contributing to the delinquency of minors.

This was the second time police responded to what they believed was a crime involving Desert Mountain High students but turned out to be a class project.

Last January, police were called to a simulated carjacking near the school. The production was ended when officers arrived with their guns drawn.