A 14-year-old boy was in custody Friday after allegedly killing his parents and trying to kill his 11-year-old sister in their Fresno County, California home, authorities said.

Deputies were dispatched to the residence in the community of Miramonte on Wednesday night on a 911 call reporting a break-in and attack, Sheriff John Zanoni said at a news conference Friday.

Deputies found the parents dead and the sister injured. A 7-year-old sibling was uninjured, and was in the care of relatives, Zanoni said.

The teenage boy told deputies someone broke in attacked family members before fleeing in a pickup, but detectives discovered inconsistencies in his story, and he was ultimately taken into custody, the sheriff said.

“He fabricated the story of the break-in,” Zanoni said.

The teen sustained a few scratches, he said, but there was no indication he had self-inflicted injuries.

The suspect was not being identified because he is a minor.

The parents were identified as father Lue Yang and mother Se Vang, both 37. The cause and manor of death were still pending, a sheriff’s spokesperson said.

The sister had severe injuries and was expected to survive after receiving trauma care, Zanoni said.

Authorities were still cataloguing weapons and were not prepared to say exactly what was used in the attacks, the sheriff said, adding that some of the multiple weapons used in the violence were not uncommon in rural areas.

Miramonte is in the Sierra Nevada mountains, about 40 miles west of Mount Whitney.

The motive has not been determined, Zanoni said. Deputies had not made previous visits to the household.

It wasn’t clear if charges had been formally filed or if the suspect has retained counsel in the case. The Fresno County public defender’s office did not immediately respond to a request for comment.

The teen was being held in a juvenile facility on allegations of murder and attempted murder, the sheriff said.

“It is extremely tragic,” he said.