LOS ANGELES: Authorities have identified the three young children who were killed in a gruesome slaying in Los Angeles over the weekend. Their mother is the suspect in their deaths and was being held in a central California jail on Monday.

The autopsies of 3-year-old Joanna Denton Carrillo, her 2-year-old brother, Terry, and 6-month-old sister, Sierra, were pending on Monday, coroner's records said.

The children's grandmother returned home from work Saturday morning and found their bodies in their apartment in the San Fernando Valley neighborhood of Reseda.

Police have not disclosed a motive or how the children were killed.

The Los Angeles Times reported that the children's father, Eric Denton, said he'd been in a custody battle with Carrillo after she began acting mentally unstable.

He had sought custody on March 1 and petitioned the court for a mental health evaluation of Carrillo. Another hearing in the case was scheduled for Wednesday.

Denton said he tried to get local authorities to intervene, but "in L.A. they wouldn't help. The LAPD would not get involved," he told the newspaper.

He said Carrillo was supposed to turn over the kids to him on Sunday.

The children's mother, Liliana Carrillo, was arrested in the Ponderosa area of Tulare County, about 200 miles (320 kilometers) north of Los Angeles, on Saturday.

Authorities said police initially received reports that Carrillo was driving her car and heading north on Interstate 5 when she got in an altercation in the Bakersfield area.

She abandoned her car and carjacked another vehicle, police said.

She is being held on $60,000 bail in the Tulare County jail on second-degree robbery charges, records said. It was not immediately clear if she had an attorney who could speak on her behalf.

The Los Angeles County District Attorney's Office did not immediately respond to a query about whether she would be extradited.

The Los Angeles Police Department's Juvenile Division is handling the case and a police captain, Chris Waters, did not immediately return an emailed request for comment Monday morning.