Gun range owner, his wife and grandson were shot dead at their Georgia home on Saturday, and police are looking for at least one armed suspect, officials said.

The incident happened on Friday night, according to the Grantville Police Department’s Facebook page. The owner of Lock Stock & Barrel Shooting Range, his wife, and their grandson were found dead when police arrived at the site at 8 p.m.

The owner of gun range Thomas Hawk, 75, his wife Evelyn, 75, and their 17-year-old grandson Luke were all killed, Grantville police said WSB-TV.

The Hawks were respected and well-known in their small, close-knit community, according to Police Chief Steve Whitlock. Lock Stock & Barrel has been owned and managed by the Hawks family. During his spring break, their grandson volunteered in the store with his grandparents.

“This is just a shock to everybody in the community,” Whitlock told The Associated Press. “We’re trying to do the best that we can to figure this out.”

No arrests have been made as of early Saturday morning, he added. According to investigators, the range’s security camera and as many as 40 firearms were also stolen.

It is being investigated by the Georgia Bureau of Investigation, but they forwarded all questions to Grantville Police when reached on Saturday. An additional law enforcement agency was summoned owing to the large number of firearms that were seized. Whitlock expressed his gratitude to the other authorities involved in the inquiry for their assistance.

“We’re just a small town, 12 officers. I’ve been here eight years and have never had to investigate anything like this. It’s been kind of hard on us. The crime rate is really, really low,” he said.

According to the ATF Atlanta office’s Twitter account, a $15,000 reward has been placed for information leading to the conviction and arrest of the murderer or killers in the case.

“ATF and our law enforcement partners will work tirelessly to bring the killer(s) to justice,” Benjamin Gibbons said in a statement. “The brutality of these senseless murders along with the fact that these killer(s) have acquired additional firearms makes solving this case our top priority.”

Any potential witnesses are urged to come forward by the police. Whitlock said that they don’t have any video footage at this time.

“Anyone having driven by the shooting range during the time frame of 530pm to 630 pm that may have seen vehicles other than a white Ford dually truck and a black Ford expedition are asked to contact the police department,” Grantville police stated in a Facebook post.