Gunman sought in father-son double murder at family business, Wisconsin police say

shooting, dead body covered with sheet, hand holding gun, do not cross tape.

(CBS) LA CROSSE, Wis. - La Crosse police are trying to find the gunman who killed a father and son inside their family photography store on Saturday, CBS Minnesota reports.

Family members identified the victims as 56-year-old Paul Petras and his 19-year-old son, A.J., who were shot to death at May's Photo at approximately 2 p.m. Saturday. Investigators said they were shot around the same time a weekend photography class was ending at the store.

According to newspaper archives, Paul Petras ran May's Photo, a family business that was started by his father. They formerly had a store in Winona, Minnesota.

The Department of Criminal Investigation is sending a team to La Crosse to help with the investigation.

"It's imperative for the community to let us know anything (suspicious) that they saw," Capt. Robert Lawrence said.

Police have not released any information on a possible suspect. Anyone with information is encouraged to call the La Crosse Police Department at (608) 785-5962.