Three people are dead in a robbery at a Coweta County gun range.

Grantville police confirmed someone shot and killed the gun range’s owner, as well as his wife and their grandson, during a robbery that happened between 5:30 p.m. and 6 p.m. Friday night.

“Let’s keep Richard Hawk and Family in our prayers,” Grantville police said in a statement.

The Bureau of Alcohol, Tobacco, Firearms and Explosives, Grantville city officials and the National Shooting Sports Foundation announced Saturday a $15,000 reward for information leading to the arrest and conviction of the shooter.

“ATF and our law enforcement partners will work tirelessly to bring the killer(s) to justice,” Benjamin P. Gibbons, Atlanta Field Division Special Agent in Charge, said.

The range is roughly 24 miles north of LaGrange and roughly 50 miles south of Atlanta.

Officers arrived at the scene at about 8 p.m. Investigators said an unknown number of suspects murdered the store’s owner and two relatives before fleeing the store with guns.

Grantville police said someone stole as many as 40 weapons and a camera DVR.

The shooting happened after hours when the range was closed.

The Georgia Bureau of Investigation has been called in to investigate. ATF agents are also assisting with the investigation.

Anyone with information can call 1-888-ATF-TIPS, email ATFTips@atf.gov or submit at www.atf.gov/contact/atf-tips.