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, Forsyth County Sheriff Duane Piper said. 

Officials identified the gunman as 32-year-old Matthew Fields. They say he was the boyfriend or perhaps husband of the woman he killed, 37-year-old Rebecca Manning. Her two boys, 8-year-old Jared Smith and 9-year-old Jacob Smith, were also killed.

Fields critically wounded Manning's father, 75-year-old Jerry Manning.

"There's no reason that any of us are ever going to understand to wipe an entire family"

- Duane Piper, Forsyth County Sheriff

"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 he and his wife 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 distributed by the sheriff's office.

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.

The home where the victims were shot is a white, single-story, double-wide that contrasts with the expansive residences in a nearby subdivision.

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.