MADISON, Wis. (AP) — A Wisconsin prosecutor has decided not to charge a police officer who shot and killed a teenager who opened fire on kids as they left their high school prom.

The state Department of Justice announced Thursday that Langlade County Special Prosecutor Galen Bayne-Allison has decided not to charge Antigo Police Officer Andrew Hopfensberger Jr. in the death of 18-year-old Jakob Wagner.

According to investigators, Wagner rode his bike to Antigo High School's prom on April 23 and opened fire as students left the dance with a rifle, wounding two people. Hopfensberger, who happened to be searching for drugs in the school parking lot with a dog, shot Wagner three times.

Hopfensberger told investigators he warned Wagner to drop his gun but Wagner pointed it at him.