Story highlights

Mary O'Callaghan was tried on one count of assault under the color of authority

Alesia Thomas lost consciousness in a patrol car, was declared dead at hospital

CNN  — 

A Los Angeles police officer has been convicted by a jury of assaulting an arrested woman who later died, according to a statement issued Friday by the Los Angeles County District Attorney’s Office.

Mary O’Callaghan, 50, was tried on one count of assault under the color of authority. She will be sentenced July 23 and could face three years in prison.

O’Callaghan was accused of assaulting Alesia Thomas who, while under under arrest, lost consciousness in a patrol car. She was later declared dead.

The incident occurred July 22, 2012, when police investigating possible child abandonment went to Thomas’ home.

Earlier, Thomas had dropped off her two children at a police station because she felt her drug abuse had made her an unfit parent, according to Los Angeles County Supervisor Mark Ridley-Thomas.

At the mother’s home, police talked with Thomas and arrested her. O’Callaghan arrived on the scene and helped fellow officers put Thomas – then wearing handcuffs and leg restraints – in a patrol car.

Video captured what happened next, the prosecutor’s office said, including “O’Callaghan kicking Thomas in the stomach and groin area and pushing her in the throat.”

Thomas lost consciousness in the patrol car, then was transported by paramedics to a hospital, where she was pronounced dead.

According to the Los Angeles Times, O’Callaghan’s attorney, Robert Rico, said his client used her foot to push Thomas into the patrol car but didn’t kick her. He said Thomas had not complied with officers’ orders.

CNN affiliate KTLA reported that prosecutors didn’t charge O’Callaghan with involuntary manslaughter because there was insufficient evidence to prove that her conduct caused Thomas’ death.

Thomas’ official cause of death was “undetermined,” according to a coroner’s report.