Erik Denton, the grieving father of three youngsters who were allegedly drowned by their mother, is urging a Pasadena judge to force psychologist Dianna Lynn Barnes to surrender the notes from her evaluation of Liliana Carrillo. The civil suit, launched in April 2022 against Los Angeles County and several officials, alleges that police and social‑service agencies ignored warning signs of Carrillo’s deteriorating mental health before the tragedy on 10 April 2021.
A Subpoena in the Shadows
On 13 August 2026 a process server handed Denton’s motion to Barnes at her Westlake Village office, demanding the release of session transcripts that could reveal whether Carrillo’s mental state was properly assessed. Barnes has so far refused, invoking a claim of privilege and insisting the records are protected from disclosure. In court filings, Denton’s lawyers argue that the psychologist’s notes are “central” to proving that the authorities failed to act on clear indicators of danger.
The Mother’s Mental Health on Trial
Carrillo, then 33, was found not guilty by reason of insanity in October 2024 for the murders of her children – six‑month‑old Sierra, three‑year‑old Joanna and two‑year‑old Terry – and was subsequently confined to a state mental health facility, where she remains under ongoing judicial supervision. Earlier psychiatric reports, including one by psychiatrist Dr David S. Rad, referenced Barnes’ diagnosis that Carrillo suffered from bipolar disorder with peripartum onset and post‑traumatic stress disorder, conditions that, according to Denton’s attorneys, impaired her moral understanding.
Legal Battle Over Government Responsibility
The lawsuit contends that Los Angeles police and county social workers neglected to share critical information about Carrillo’s escalating condition, thereby breaching their duty to protect the family. Denton alleges that the failure to act on repeated warnings constitutes negligence that directly contributed to the children’s deaths. The forthcoming hearing on 14 September will determine whether the subpoena can compel Barnes to hand over her records, a decision that could set a precedent for how mental‑health evidence is treated in future civil actions against public agencies.
Why It Matters
If the court orders the release of the psychologist’s notes, it could expose systemic lapses in how mental‑health warnings are communicated between police, social services and the courts, prompting a long‑overdue review of safeguarding protocols. Conversely, a ruling that upholds privilege may reinforce the secrecy surrounding therapeutic records, leaving families like Denton’s without a clear path to accountability. The outcome will resonate far beyond this single case, shaping the balance between patient confidentiality and the public’s right to know when governmental inaction leads to tragedy.
