An internal report found that two Fullerton, California, police officers who were acquitted of criminal wrongdoing in the death of a mentally ill homeless man in 2011 violated their department's use-of-force policy.

The report was not presented to the jury because of state laws protecting the confidentiality of peace officers' disciplinary records.

Kelly Thomas died after a violent struggle with Fullerton Police Department officers in July 2011.

The 2012 report came to light recently after it was included in a legal filing in a wrongful-death lawsuit brought by Thomas' father against the city, the Police Department and others. That trial is slated for later this month.

A 33-minute surveillance video shows the officers hitting, kneeing and firing an electric stun gun at Thomas as he cries out for his father.