Johnny Lewis Beat, Dismembered CAT

Johnny Lewis murdered his landlady and then fell to his death -- but he also viciously took the life of the landlady's cat by beating it to death and DISMEMBERING it in the process ... TMZ has learned.

TMZ broke the story that Lewis -- who appeared on "Sons of Anarchy" -- seemed to be on PCP or meth, because he had exhibited superhuman strength as he fought two neighbors immediately after committing murder.

Law enforcement sources tell us Lewis went wild on landlady Catherine Davis' cat ... kicking and beating the life out of the animal and "tearing it apart." Law enforcement tells us Lewis did NOT use a weapon, but rather his bare hands and feet.

Lewis is the only suspect in the murder and cat killing. We're told cops are confident -- Lewis was the culprit.

'Sons of Anarchy' Creator Johnny Lewis Was On a 'Destructive Path'

"Sons of Anarchy" creator Kurt Sutter -- who also plays "Big Otto" Delaney on the show -- isn't one bit surprised by Johnny Lewis' death yesterday ... claiming the actor had long been on a "destructive path."

Sutter posted a statement on Twitter this morning about Lewis' death, calling it "a tragic end for an extremely talented guy, who unfortunately had lost his way."

Sutter wrote, "I wish I could say that I was shocked by the events of last night, but I was not."

He added, "I am deeply sorry that an innocent life had to be thrown into his destructive path. Yes, it's day of mourning, but it's also a day of awareness and gratitude. Sadly, some of us carry the message by dying."

As we reported, Lewis was truly on a "destructive path" before his death -- being convicted of several violent crimes before allegedly murdering his landlady yesterday.

Johnny Lewis String of Violent Crimes Before Alleged Murder

Johnny Lewis -- the "Sons of Anarchy" actor suspected of murdering his landlady Wednesday before falling off a roof to his death -- was convicted of several violent crimes in 2012 ... TMZ has learned.

According to official records, Lewis committed felony assault with a deadly weapon on January 3rd. The records don't specify the details of the crime, but they do show he was subsequently ordered to complete a rehab program for "treatment of mental health and/or drugs and alcohol."

The records also indicate Lewis was arrested on February 10th. Law enforcement sources tell us, he sucker-punched a man on his way out of a yogurt shop for no apparent reason.

Eight days afterwards, on February 18th, Lewis was arrested again for burglary. According to law enforcement sources, he had tried to break into a woman's house through a window, claiming he was looking for a friend ... but when the woman called cops, he took off.

Lewis was convicted of felony assault following his January arrest, and sentenced to a year in county jail. Lewis was also convicted of battery and burglary following his February arrests, and sentenced to 303 days in jail for those two crimes.

It's unclear exactly how many days he served and whether he spent the majority of his time in jail or in rehab. Lewis was ultimately released from jail SIX DAYS AGO on September 21st.

(FYI -- The mug shot for Lewis' felony assault arrest is unavailable because the LAPD doesn't release mugs.)

Johnny Lewis Fresh Out of JAIL Before Murder

Johnny Lewis -- the man suspected of murdering his 81-year-old landlady Wednesday -- was 6 days out of jail before the killing ... TMZ has learned.

Lewis was released from L.A. County Jail on September 21. We're told he had several criminal cases filed against him at the time of his death.

We do not know the nature of the offenses, but law enforcement sources tell TMZ ... the "Sons of Anarchy" star was also recently in rehab.

What's more ... we're told a dead cat was found in the house where Lewis lived with the landlady -- and the home was ransacked. Police are investigating, but Lewis is also suspected of killing the cat.

As we reported ... law enforcement sources tell TMZ they believe Lewis was either on PCP or Meth at the time of the murder. The 2 people who fought Lewis before he fell to his death from a roof told cops the actor exhibited "superhuman strength."

'Sons of Anarchy' Actor Suspect in BIZARRE L.A. Double Death

7:08 AM PT -- Law enforcement sources tell TMZ ... cops believe Johnny was on drugs-- either PCP or meth -- at the time he allegedly killed a woman and then fell to his death.

Sources tell us ... after allegedly killing the 81-year-old woman, Johnny had fought with two men for 3 to 4 minutes ... hurting at least one of them

We're told Johnny initially used a 2x4 to attack the men ... and then used his bare hands.

Law enforcement sources say the men he fought with say Johnny showed "super-human strength" and was "phenomenally strong."

We're told Johnny tried to break into the house of one of the men ... and it took 3 people to hold him back.

One source tells TMZ ... Johnny had gone to a neighbor's home to introduce himself earlier in the day.

Neighbors tell us Johnny had lived in that house before, moved away, and then came back.

Neighbors who knew Johnny say he was a "nice guy."

Johnny Lewis -- who had big roles on "Sons of Anarchy," and "The O.C." and once dated Katy Perry -- was found dead yesterday ... and his body was discovered at the same L.A. property as an 81-year-old woman he's suspected of murdering ... TMZ has learned.

According to our law enforcement sources, 28-year-old Lewis was found in a driveway Wednesday morning in the Los Feliz neighborhood -- and the elderly woman who owned the home was found dead inside ... the victim of a homicide. Investigators say they believe Lewis beat the woman to death.

According to multiple reports, neighbors heard the 81-year-old woman screaming ... and then saw a young man outside her home attack 2 other people with a piece of wood ... before he climbed onto the roof and fell to his death.

Lewis was renting a room from the 81-year-old victim.

Law enforcement sources tell us Lewis is the sole suspect in the woman's murder, and they are not looking for other possible suspects.

Lewis dated Perry back in 2006 -- and attended numerous Hollywood events together.

Lewis played Kip 'Half-Sack' Epps on "Sons of Anarchy" for 2 seasons, and also had one-off roles on "Criminal Minds" ... "Bones" ... and "CSI."

Ex-Hells Angel: 'Sons of Anarchy' Was MY Idea!

A motorcycle war has broken out over the hit FX show "Sons of Anarchy" -- because the former NYC chapter head of the "Hells Angels" claims the network jacked his idea and screwed him out of millions.

TMZ has obtained a lawsuit filed by Chuck Zito -- in which the bike gang member-turned-actor claims he developed an idea for a show about an "outlaw motorcycle club" back in 1998 and pitched it to FX in 2004.

In the docs, Zito claims he entered into an "implied-in-fact contract" with FX which guaranteed if they used his ideas for a TV show, Zito would be "reasonably compensated and afforded appropriate screen credits." Zito claims FX eventually passed on the project.

So when FX began developing "Sons of Anarchy" in 2006 -- Zito was pissed ... claiming "Sons" was "substantially similar" to his motorcycle show idea.

Now, Zito claims FX is obligated to pay him more than $5,000,000 for breaking the "implied-in-fact" contract.

FX had no comment on the lawsuit.