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.

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.

Investigators are looking into whether Lewis may have been under the influence of C2-I - a new designer drug known as "smiles" - during the altercation, sources said. The illegal drug causes hallucinogenic effects, according to the Drug Enforcement Administration, and was linked to the deaths of two North Dakota teenagers this summer.

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.

Johnny Lewis was released from jail less than a week ago and pleaded no contest Aug. 8 to one count of assault with a deadly weapon and was sentenced to 365 days in Los Angeles County jail with three years of probation, a district attorney's office spokeswoman said. Nine days later, he pleaded no contest to a burglary charge in separate case and received 291 days in jail.

He was released from custody Friday afternoon, online jail records show. It was not immediately clear why he was released.

The drug is usually sold in tablets or powder form, which users often mix with chocolate before eating.

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