Investigators believe "Sons of Anarchy" actor Johnny Lewis brutally killed his elderly landlord Wednesday before falling to his death as he tried to escape police whose sirens he heard approaching.
It could be weeks before police understand the cause of what they say was a violent rampage by Lewis, 28, that led to the death of Katherine Davis, 81.
Davis died from "blunt head trauma and strangulation," according to preliminary findings from the autopsy conducted Thursday, the Los Angeles County Coroner's office said.
Police suspect drugs were involved, but "we don't have any hard evidence that says he was on anything right now," LAPD Commander Andrew Smith said.
Toxicology findings from the autopsy conducted Thursday by the coroner will be crucial to determining if the actor was under the influence of drugs, Smith added. It is expected to take at least a month before the report is done.