LA CROSSE, Wis. -

La Crosse police are investigating a shooting at a photography store that left a father and son dead.

Paul Petras, 56, and his son A.J. Petras, 19, were shot to death in May's Photo store, 425 Main Street, on Saturday.

Capt. Robert Lawrence said the homicides occurred about 2 p.m. Saturday, roughly the same time a photography class at May's Photo ends and the store closes.

Lawrence said Saturday that police had made no arrests and no one immediately returned a call from The Associated Press Sunday for an update.

According to newspaper archives, Paul Petras ran the shop started by his father. They formerly had a store in Winona, Minn.

AJ Petras was a 2011 graduate of Aquinas High School and a member of the ski team.

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