KATY Perry's ex who allegedly murdered his landlady, her cat and then himself, had deep ties to Scientology and its drug abuse program.

A photo obtained by TMZ shows the Sons of Anarchy star Johnny Lewis, 28, at the Scientology substance abuse program, called Narconon, which he reportedly spoke at back in 2004.

The website reports that Lewis' mother used the principles of the program to keep him off drugs.

However, Lewis had been in rehab earlier this year and those who witnessed the bizarre scene this week at the home he rented from his 81-year-old murdered landlady, Catherine Davis, claim he was "on PCP or meth" at the time.

TMZ said the photo of Lewis on the Scientology website was removed after they made inquiries and an official said Lewis had not been an active member of the church for years.

His father, Michael Lewis, was considered one of the highest members of the church and reportedly wrote a movie script with the church's founder L. Ron Hubbard about the leader's discovery of Dianetics, the idea of a metaphysical relationship between the mind and body practiced by Scientologists.

Lewis, who played Kip "Half-Sack" Epps on Sons of Anarchy, was released from jail just a week ago.

Police said he was the only suspect in the death of Davis.

Lewis died after climbing to the roof of the home in the affluent Los Feliz suburb; he had either jumped or had fallen to the ground.

The deaths came four months after a probation officer expressed grave concerns about Lewis' mental health, writing that he was "very concerned for the well-being of not only the community but that of the defendant."

Court records detail Lewis' descent from January 2012, when he attacked two men and hit them in the head with a bottle, through August, when he acted as his own attorney and pleaded no contest to felony assault.

By that point he had been arrested three times for incidents ranging from trying to break into an occupied home in Santa Monica, California, to resisting arrest. He had been sent to treatment programs that specialised in drug and alcohol addiction as well as mental illness.

A May 17 probation report states that "the defendant suffers from some form of chemical dependency, mental health issue and a lack of permanent housing. Given this, (Lewis) will continue to be a threat to any community he may reside."

Another probation officer had written two months earlier, "Obviously defendant's behavior is out of control and needs counseling afforded by a professional."

Lewis remained on supervised probation at the time of his death.

Lewis' attorney Jonathan Mandel said the actor had serious mental issues that seemed to surface fairly recently. He said Lewis' parents and others had tried desperately to help him.

"Johnny Lewis had a lot of problems, a lot of mental problems," Mr Mandel said by phone Thursday. "I recommended treatment for him but he declined it."

He continued, saying: "I give a lot of credit to his parents. They were really strong in trying to help him out. They really went to bat for him, but I guess they just couldn't do enough."

Neighbours said they called the police after they heard a woman screaming and saw Lewis attack two men with a plank of wood out the front of Davis' home.

Two men, a neighbour and a repairman, were beaten in the attack, which started when Lewis tried to break into the neighbour's house.

The men said Lewis showed "super-human strength" that it was like "hitting him with a fly swatter".

Police suspect he was on drugs at the time.

Lewis had a career spanning more than a decade, mainly in small roles, dated Katy Perry in 2006 and regularly appeared at red carpet events with her. He appeared in two seasons of Sons of Anarchy before his character was cut from the show.

Kurt Sutter, creator of Sons of Anarchy, said he was not entirely surprised by Lewis' death.

"(This) 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. I am deeply sorry that an innocent life had to be thrown into his destructive path,'' Sutter said.

"Yes, it's (a) day of mourning, but it's also a day of awareness and gratitude. Sadly, some of us carry the message by dying."

A source at the show told E! online: "It wasn't a secret that Johnny had issues he was dealing with. No one could have expected it would end so tragically, though. Everyone is in shock."

The Church of Scientology said Lewis had not been active with the church for "many years", and denied he had attended Narconon.

"This is a terrible tragedy," the church said in a statement.

"Out of respect for the privacy of the affected families, we are not commenting further other than to state that it is apparent that the scourge of drug addiction has claimed more lives.

"We are saddened that this tragedy is being insensitively exploited by a handful of anti-Scientoligists whose only concern is promoting themselves and their hate filled agenda."