John “Rusty” Houser, the Lafayette theater shooter, suffered for decades from recurring mental health problems, including manic depression and bipolar disorder, according to law enforcement officials and several people who knew him. He became something of a drifter after being evicted from his Alabama home last year — a residence he trashed after it was foreclosed upon and purchased.

Houser, 59, had a relatively minor criminal history before he fatally shot two people, injured nine others and killed himself Thursday night at The Grand 16 Theatre during a showing of “Trainwreck.” But he frequently became embroiled in heated civil disputes and, on more than one occasion, exhibited what Phenix City Police Chief Ray Smith described as “strange behavior.”

“He was known to us,” Smith said Friday as federal law enforcement officials sought to track down Houser’s family members and searched the gunman’s former residence here.

Some who knew him described him as volatile and dangerous. In Houser’s online life, his beliefs were extreme, expressing fondness for white supremacist David Duke, exposing anti-Semitic views and celebrating Oklahoma City bomber Timothy McVeigh, according to the Southern Poverty Law Center, which reviewed his Internet message board posts.

Heath Taylor, the Russell County sheriff, said the Sheriff’s Office had denied Houser a concealed-carry pistol permit in 2006 because of a series of complaints filed against him, including ones for domestic violence and arson.

The gun Houser used in the shooting was a .40-caliber handgun, purchased legally at a pawn shop, officials said.

What, exactly, triggered Houser’s rampage remained unclear Friday. Lafayette Police Chief Jim Craft said the authorities still had not determined a motive for the killings.

Houser, whose wife filed for divorce this year, had been living in a motel in Lafayette, where investigators said they recovered wigs and disguises. His car, found in the parking lot near a theater exit after the shootings, had a switched license plate.

In 2008, Houser’s family filed court papers seeking a protective order against him in Carroll County, Georgia. Houser, they said, had “exhibited extreme erratic behavior,” made threats and “perpetrated various acts of family violence.”

Houser’s wife, Kellie Houser, told police that year that her husband would sometimes forget to take his daily medication and that she once removed “all of the guns from their house in Phenix City,” according to a police report.

In Columbus, Georgia, just across the Chattahoochee River from Phenix City, Houser was described as a political rabble rouser who was fanatically anti-taxes. Mark Hogencamp, who knew Houser in Phenix City, recalled him as “a troubled guy” who had been struggling with depression.

“He seemed to be more and more unstable,” Hogencamp said.

Houser came from a well-respected Columbus family and in high school had been an outgoing “bad boy, but in a good way,” said Sharon Fowler, who dated him for a few months at the time.

The younger brother of two never seemed to measure up to the success of his family members, said former Columbus Mayor Bobby Peters, who is now a Georgia Superior Court judge. Houser, a fast-talking, self-appointed community “watchdog,” Peters said, alternately wanted to be a lawyer and open a nightclub, neither of which transpired.

He was inexplicably fixated on making sure movie theaters showing pornography were restricted, Peters said. “He was trying as hard as he could to get his niche in the community, and somehow, it just didn’t work out.”

Fowler, the ex-girlfriend, said she had not sensed that Houser suffered from mental health issues as a young man. But last year, when she considered buying his foreclosed home, she said Houser exhibited a number of disturbing red flags. For some reason, she said, the man she had known for years did not even recognize her until her third visit to the property.

Houser moved himself into one room of the four-bedroom, three-bath house, she said, and, bizarrely, allowed a massive population of koi fish to populate his in-ground pool.

“It was so packed with koi that it was just unbelievable,” she said. “He said he liked it that way.”

The man who did purchase Houser’s home, Norman Bone, said the Houser of recent months was a totally different man from the person he met some 25 years ago. Bone, 77, bought the Russell County property but said he had to involve law enforcement to get Houser to vacate the premises. When Houser finally left, the house had been nearly destroyed.

“He junked the house,” Bone recalled. “Anything you could think to do to the house, he did it. He put cement down every sink, every lavatory, every commode, every bathtub. He took dead fish and chicken and put it in the air-conditioning vent. He went around every receptacle, every switch and painted it with purple epoxy.”

Over the years, Houser had been a regular face at local government meetings, where he spoke out against various tax proposals. He ran for Muscogee County tax commissioner in 1996, a position previously held by his father, but later withdrew from the race.

That year, he was accused of illegally stealing his opponents’ campaign signs, a claim he denied. He told the Columbus Ledger-Enquirer newspaper the signs had been placed illegally on city and private property and that he had permission from the property owners to remove them from the premises.

In interviews, former acquaintances said Houser long had shown disturbing tendencies and that he appeared to be close to the edge. Vince Woodward, who was chairman of the local Republican Party about the time Houser ran for office, described him as a “very troubled” conspiracy theorist. Though it has been at least 15 years since they spoke, he recalled that Houser had frequent mood swings that he perceived to be symptoms of bipolar disorder.

“You could feel something was very wrong with him,” Woodward said. “You could feel a meanness.”

Fife Whiteside, an attorney who sat on the School Board for several years, was often on the receiving end of Houser’s anti-tax vitriol. The School Board proposed two tax proposals in the 1990s, while Whiteside was in office, that put the two at odds. He recalled the night the first tax proposal failed that he had been working late in his office.

“I look up, and his face is peering into my window,” Whiteside said. “It became a kind of famous story because Rusty was just crawling around outside in my bushes.”

John Swearingen, a former attorney in Columbus, said Houser attempted in 1989 to hire a man named Robert Penad — who ended up being a police informant — to set Swearingen’s Third Avenue law office on fire because Swearingen’s firm represented a movie theater that showed pornography.

“He didn’t like that, so he wanted my office burned,” Swearingen said. “He’s always been a little unbalanced, to say the least.”

According to court transcripts, Penad said Houser promised to pay him $100 to torch the property “to quote, unquote save the world, bring law and order.”

Houser’s mental competency was called into question during that proceeding, court records show, and a judge ordered a psychiatric evaluation, but he was ultimately deemed competent. A Muscogee County grand jury ultimately declined to indict Houser.

Radio host Doug Kellett, who had a show for about 10 years in Columbus, said Houser was a “gadfly type” who made a few appearances on his show. Houser boasted on his own LinkedIn page that he was a guest on Kellett’s show 13 times, describing himself as “an unwanted guest and budget cutter at 7 Columbus Water Works board meetings, and 22 Columbus City Council meetings.” He credited himself with “millions saved and mega-thousands discovered misappropriated.”

“He wasn’t memorably weird or crazy,” Kellett recalled. “There were so many tax issues back then, it was very contentious. He was part of the vocal audience against it.”

Woodward saw a lighter side to Houser, saying aside from his strident political views, he was mostly a regular guy, one who could be funny and joke around.

“When he was identified, at first, I was in total shock,” Woodward said. “But the more I’ve thought about it, over the past couple hours, I can see his behavior in the past, and it’s not quite as shocking.”

Ed Hostilo, a close friend of Houser’s who saw him as recently as two years ago, said the two bonded over political activism. But he said Houser frequently took it to an uncomfortable level.

“The guy I knew was always fun, always making jokes and shaking everybody’s hand,” Hostilo said. “But if there was an indication that something was wrong, it was that he would go off on a tirade for 10 minutes about something political. We’d have to calm him down, quite literally.”

Hostilo noted that Houser was educated. He was both a certified public accountant and he had a law degree. But he made his living painting houses and owning bars.

He ran a beloved bar called Peachtree Pub where many of his friends would hang out. After the bar closed at night, Houser was known to shut the doors and let his friends drink for free while he poured the drinks.

But Hostilo noted that Houser wasn’t always mellow. At a public water board meeting about a rate hike, Hostilo recalled his friend “went off on homosexuals controlling the city.”

“If you had told me the other day that five politicians on a city council had been shot, then I would have believed it was Rusty,” Hostilo said. “But when I heard it was innocent people in a movie, I just couldn’t believe it.”

Two years ago, the two crossed paths at a barbecue restaurant and Houser sat down at his table. He said Houser immediately started complaining about the Obama administration and decrying the attack on Confederate heritage.

“He said people were out to destroy the Confederacy, that they want to destroy our heritage,” Hostilo recalled. “And I said, ‘Who?’ and he said, ‘the homosexuals.’ ”

One thing none of Houser’s former friends understand is why he was in Louisiana and how he could be described as a “drifter” by law enforcement. Hostilo said he believed Houser had been financially secure.

“I always understood his family was very wealthy and that he was very wealthy,” Hostilo said. “He’s not the kind of person I would have thought would drift away from everyone he knew.”

Houser’s sometimes radical political beliefs can be found splashed across the Web attributed to his full name.

On a Twitter account created in March 2013, a John Russell Houser with the handle @jrustyhouser had two single tweets:

“The Westboro Baptist Church may be the last real church in America (members not brainwashed),” he wrote June 5, 2013, talking about the church that protests military funerals.

The same day, he tweeted “If you don’t think the internet is censored, try reading a newspaper from a country that hates liberals the way I do.”

On a website called PoliticalForum.com, a Rusty Houser from Phenix City, Alabama, frequently posted using his full name.

In one post, he chillingly refers to his own death while fighting for his beliefs.

“It is true that the US is about to fall. I will be in fear at that time as will everyone else, but not in a fear which resembles that of the leaders of foolishness and the brainwashed that follow. Truth carries with it an understanding of death. Rather than live without it, I will take death. My greatest fear is that I could die making a decision for the good of myself against everyone else.”