RESEDA (CBSLA) — Court documents obtained Monday by CBS Los Angeles show 30-year-old Liliana Carrillo, the woman suspected in the deaths of her three children, was involved in an ongoing custody battle with their father, Erik Denton.

Liliana Carrillo, 30, is seen here in this undated photo with her three children. (Family photo)

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According to filings in Tulare County Superior Court, Denton said he had noticed a change in Carrillo’s behavior over the past few months.

“On Feb. 25, Carrillo took our three children and took all their legal documents, including their birth certificates, and refuses to disclose their location,” a March 1 filing said.

In that filing, Denton sought custody of their children — 3-year-old Joanna, 2-year-old Terry and 6-month-old Sierra — and petitioned for Carrillo to undergo a mental health evaluation.

Less than two weeks later, on March 12, Carrillo sought a temporary restraining order against Denton in Los Angeles County.

“This is the kind of case that every family law practitioner just dreads,” Alexandra Kazarian, a legal analyst, said. “Looking at the documents, it looks like a couple that’s going back and forth during a really tough time in their relationship. Both sides seem to be lodging some pretty serious claims against the other side.”

In the filings, Denton said Carrillo was experiencing psychosis and at some point thought she was solely responsible for the COVID-19 pandemic and accused him of doing something inappropriate with one of their children.

“It’s really hard to know who’s telling the truth, who’s exaggerating and what steps you need to take to protect the children,” Kazarian said. “How does a judge on a bench, who’s hearing this allegations on paper for the first time, how does a judge make that decision? These are snap decision that people make.”

Anna Carrillo, sister of Liliana Carrillo, Monday asked people to respect the families while they grieve the loss.

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“Respect the families, both families, because we are both suffering,” she said. “This is a great loss for all of us.”

She also shed some light on the couple’s legal filings.

“Erik Denton and his family had their concerns for the safety of his children and for her,” she said. “My sister was having concerns for the safety of her children in his care too.”

Anna, who came to the site of the memorial with brother, Javier, said the court system failed both Denton and her sister.

“We were asking for help, and there was no follow-up,” Javier said.

Kelly Chang Rickert, a family law attorney, said a more helpful solution for families going through mental health crises would be to sit down with a psychologist and a mediator.

“Litigation is not that solution,” she said. “Family courts don’t help you.”

She said the court petitions being filed in different counties also complicated the trail of paperwork.

On March 26, a judge ruled the couple would continue under a joint custody agreement. Another hearing in the case had been set for Wednesday.

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The Los Angeles Police Department said Monday that it was seeking to extradite Carrillo to L.A. County after “conferring with the L.A. County District Attorney’s Office.”