Authorities said they still didn’t know Friday what prompted a man to apparently kill his two young boys and their mother before killing himself at the small eastern Mississippi home they shared, but they were looking into whether the couple had past domestic problems.

Lauderdale County Sheriff Billy Sollie said investigators will begin Monday looking into whether the couple had past problems. Courthouses in Mississippi were closed Friday for the Christmas holiday.

“We’re going to start to verify any court records for any domestic issues filed by either party,” Sollie said.

Sollie told The Associated Press that David Ross Killough Sr., 26, had been living in the small home for some time and the mother and children appeared to have been living in the home about a week. The mother was identified as Angelica Lynn Milan, 25. The children were identified as 5-year-old David Ross Killough Jr. and 4-year-old David Reese Killough. Sollie said the body of David Killough Sr. was found in the bedroom with one of the boys. The sheriff would not say which one of the boys was in the room. Milan’s body was found on a couch in the living room and one child’s body was found in a hallway.

“We still don’t know what prompted this,” Sollie said.

The bodies were taken to Jackson for an autopsy.

“We’re absolutely certain three of the four were shot. The child in the bedroom … it’s wasn’t so obvious. The autopsy will sort that out for us,” Sollie said.

Killough’s father, who was also living in the home outside Meridian, found the bodies when he returned from work around 4:30 p.m. Thursday, Sollie said.

Lauderdale County Coroner Clayton Cobler said the apparent murder-suicide took place between 7 and 7:30 a.m. Thursday. The handgun was found near the man’s body. The couple was not married.

“This is just a terrible thing to happen anytime of the year but for it to be now makes it that much more difficult for this family and others,” Sollie said.

Neighbor Ashley Castillo told WTOK-TV in Meridian that the boys often played outside and pushed their dogs in a red wagon up and down a nearby hill.

“They were sweet little innocent kids that this should have never happen to,” she said.