"It's a terrible tragedy," says a police spokesman after the discovery of Johnny Lewis's body

Sons of Anarchy actor Johnny Lewis fell to his death from a building in Los Angeles – moments after he allegedly beat his landlady, an 81-year-old woman, to death, authorities say.

Lewis, 28, who played Kip “Half-Sack” Epps on the FX show and who once dated Katy Perry, was found lying in a driveway in the Los Feliz neighborhood near Hollywood on Wednesday, while a woman identified as Catherine Davis was found dead of apparently blunt force trauma inside the building.

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The upstairs part of the building had been ransacked. Police also found the body of a cat that had apparently been beaten.

“It’s a terrible tragedy as far as we’re concerned and were digging into the bottom of it,” LAPD spokesman Andrew Smith tells PEOPLE.

Lewis had been released from jail just days before. The actor pleaded no contest Aug. 8 to assault with a deadly weapon and then on Aug. 17 he pleaded no contest to burglary, according to court records.

He was sentenced to a year in jail in the first case and 291 days in the second, but given hundreds of days credit for time already served and good behavior. He left a San Fernando Valley jail at 4:05 p.m. on Sept. 21.

Five days later, officers responding to a 911 call of a woman screaming were told that Lewis had fought with two men – it wasn’t clear if this was before or after the landlady was killed – and that Lewis died after a fall, possibly from a wall or balcony, according to police.

Detectives have concluded that Lewis killed Davis, and they are not looking for any other suspects, says Smith. There was no immediate indication of what the motive for the murder was.

“It was a tragic end for an extremely talented guy, who unfortunately had lost his way. I wish I could say that I was shocked by the events last night, but I was not,” Sons of Anarchy creator Kurt Sutter wrote on his website. “I am deeply sorry that an innocent life had to be thrown into his destructive path.”

A source close to Lewis, however, was surprised by the tragic events.

“I’m shocked by this; he was always pretty quiet. The only times I saw him angry is with regards to his character on the show,” the source tells PEOPLE. “I know at the end he got really annoyed with the story line. He felt like his character was becoming a weekly joke and he didn’t like it.”

Lewis, who also appeared on shows including The O.C., Criminal Minds, Bones and CSI, dated Perry in 2006.