Authorities in Southern California reportedly received multiple warnings about the mental state of a mother in the months before she allegedly killed her three children.

Liliana Carrillo, 30, was "extremely paranoid" and had "lost touch with reality," her ex-boyfriend and the kids’ father, Erik Denton, said in court papers, the Los Angeles Times reported Monday. He said that Carrillo made bizarre claims that she was "solely responsible" for the COVID-19 pandemic, and that he was part of a pedophile ring.

CALIFORNIA MOTHER SUSPECTED OF KILLING 3 KIDS 'UNWELL' FOR MONTHS, FAMILY MEMBER SAYS; FATER 'DEVASTATED'

He also said in petitions to a Tulare County judge, and repeated in an interview with the Times, that Carrillo struggled with postpartum depression for years, expressing thoughts of suicide and often self-medicated with marijuana.

Liliana Carrillo, 30, was arrested Saturday after a manhunt. She was being held in a central California jail.

Liliana Carrillo, 30, was arrested Saturday after a manhunt. She was being held in a central California jail. (LAPD)

Denton’s cousin, Teri Miller, spoke with Fox 11 Los Angeles on Sunday, saying that Denton had been battling Carrillo for custody of the boy and two girls for months and repeatedly reached out to the Department of Children and Family Services (DCFS) and police because he knew Carrillo "needed help."

"Liliana was very sick, and this is not – she was not herself, and it's been going on for several months that she has been unwell," Miller said, adding that the system has failed both Denton and the children.

The Times confirmed that L.A. County’s DCFS received at least two separate reports earlier this year involving the family after speaking with Denton and his family, and reviewing court documents.

Denton and Miller told the paper that they had spoken with L.A. County social workers several times about the children’s safety. They also said that they called the LAPD and asked that she be taken to a mental health facility for treatment.

Photos, candles, flowers and balloons are placed as a memorial for three children who were killed at the Royal Villa apartments complex in the Reseda section of Los Angeles, on Monday, April 12, 2021. (AP Photo/Richard Vogel)

Photos, candles, flowers and balloons are placed as a memorial for three children who were killed at the Royal Villa apartments complex in the Reseda section of Los Angeles, on Monday, April 12, 2021. (AP Photo/Richard Vogel)

Documents also showed that a Tulare County judge granted Denton physical custody of the children after he told the judge last month that he feared for their physical and mental well-being.

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Despite the order and concerns from Denton and his family, social workers decided to allow the children to stay with their mother, the Times reported, citing records and interviews.

The bodies of the children were discovered by their grandmother at their Los Angeles apartment when she returned home from work Saturday morning. Carrillo was arrested hours later in Tulare County, about 200 miles north of Los Angeles, after a massive manhunt.

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.

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

Fox News’ Danielle Wallace and The Associated Press contributed to this report.