Two teenage brothers suspected of fatally stabbing their parents and three siblings ranging in age from 5 to 12 years old were arrested in Broken Arrow, Oklahoma on Wednesday, the Associated Press reports.

18-year-old Robert Bever and his 16-year-old brother allegedly ran out a back door when officers responding to a 911 call arrived at the home were the five bodies were found. The teenage suspects were reportedly captured about an hour later in a wooded area during a police dog-assisted search.

According to police, an unharmed 2-year-old and a wounded 13-year-old girl were also found at the scene. From NBC News:

Police went to the house after emergency operators received an “open 911 call,” where the line is connected but there’s no one speaking, at 11:30 p.m. local time on Wednesday, [Broken Arrow Police Cpl. Leon] Calhoun said.

The arriving officers heard moaning from behind the front door of the home, they forced their way inside and found the injured 13-year-old, who apparently made the 911 call, and pulled her to safety, Calhoun said.

Authorities say they are still trying to determine a motive for the slayings.

“Anytime someone murders their family members as young as 5, I don’t see how there could be any type of mental process to that to justify anything,” Broken Arrow Police Sgt. Thomas Cooper told NBC News.

[Image via Broken Arrow Police Department]