Authorities detained a 17-year-old girl after three people were found slain in Fullerton over the weekend. The horrific crime scene was discovered after a child called 911, police said.

The 17-year-old daughter of at least one of the victims had been sought as a missing and “at-risk” person, according to the Fullerton Police Department. At the same time, the girl who was detained* has not been identified because state law prevents it, cops said. “State law prevents law enforcement from releasing names of juveniles arrested for crimes,” Sgt. Jon Radus told reporters.

Josh Acosta, 21, of Fort Irwin, and Frank Felix, 25, of Sun Valley, were arrested on suspicion of murder, police said. They were booked in lieu of $1 million bail each. A neighbor told Fox 11 News that one of the suspects had been dating the once-missing* girl against the wishes of her guardians. “The suspects and family are known to each other,” Radus said.

The victims were identified as 34-year-old Christopher Yost, 39-year-old Jennifer Goodwill Yost and 28-year-old Arthur William Boucher, who sometimes stayed with the family, according to reports.

Police would not reveal how the three died. Two children were in the home where the violence took place, police said. They were unharmed. A young half-sister of the once-missing teen was the one who called authorities, according to reports. Neighbors reportedly heard gunfire in the middle of the night.

The child who called authorities in the morning reported that her parents “died,” police stated. Officers responded to the 400 block of South Gilbert Street at 8:21 a.m. Saturday based on that call, police said.

“The Fullerton Police Department has committed numerous resources and personnel to bring those responsible for this horrendous crime to justice,” the department stated last night. “Within the last 24 hours, detectives have followed up on leads, conducted surveillance, and written and served search warrants in connection with this crime from South Orange County, to Los Angeles and the San Fernando Valley, to Fort Irwin and Barstow.”

Anyone with information on the case was encouraged to call Fullerton detectives:  714-738-5361.

*Corrected. We wanted to clarify that police are not saying the once-missing girl and the detained teen are the same person.

John Acosta, 21; Credit: Fullerton PD

John Acosta, 21; Credit: Fullerton PD

Frank Felix, 25; Credit: Fullerton PD

Frank Felix, 25; Credit: Fullerton PD

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