SUWANEE, Ga. (AP) — A gunman killed a woman and two children and critically wounded another man before killing himself inside a suburban Atlanta home Wednesday, a sheriff said.

The shooter and the victims all lived at the house, and the gunman was known to officers from previous arrests for minor crimes, Forsyth County Sheriff Duane Piper said. He would not release the gunman’s name, details of his previous run-ins with the law or say how the victims were related.

“We’d like to find a motive. There’s no reason that any of us are ever going to understand to wipe an entire family. We have absolutely no clue at this point what precipitated it,” Piper said.

A relative in another county called 911 about 6 a.m. Wednesday because they were worried about the family. The man who called said his wife was on the phone with her son and her son said he had shot four people and was going to kill himself, according documents detailing the call.

The caller said he and his wife were headed to the home and were 30 minutes away. The dispatcher said the caller advised of his wife: “She will be the only one that can talk to him.”

The identifying information in the documents was redacted.

Deputies found the shooter and two children under the age of 10 dead inside the home from gunshot wounds. A nearby business reported hearing gunshots around the time of the shooting.

A woman died from gunshot wounds on the way to the hospital and another man was in critical condition, Piper said.

Piper said it appeared all the victims lived at the home — a white, single-story, ranch-style house that contrasts with the expansive residences surrounding it.

The area of the shooting, on Old Atlanta Road about 30 miles northeast of the city, includes some of metro Atlanta’s most exclusive neighborhoods. The road winds past golf course communities in a heavily wooded area.

The house is a few yards from the entrance to the Olde Atlanta Club, a golf course community along the Chattahoochee River.