He also left an online record of far-right, anti-government ideas that alarmed the Southern Poverty Law Center.
Houser praised Hitler for his "pragmatism" and lauded former Ku Klux Klan leader David Duke and the Westboro Baptist Church, among others, the SPLC website said.
CNN could not independently confirm that Houser posted these opinions.
There was another side to Houser. He earned a law degree, operated taverns, ran for public office and loved political debate. He was something of a public figure in his hometown of Columbus, Georgia.
His brother, Rem Houser, told CNN on Friday he and John Houser were not close.
He last talked to his brother about a month ago.
"He just needed some money to continue moving on, living, surviving, so we gave him some, and that was the last we heard of him. We hadn't heard of him in probably 10 years prior to that, and hadn't heard from him since," Rem Houser said.
John Houser spent much of his life in towns along the Georgia-Alabama state line. He grew up in a political family in Columbus but also had owned a house across the border in Phenix City, Alabama.
A record of public posturing
He left a trail of erratic behavior.
His last known major legal problem came last year when he was evicted from the house he owned in Phenix City. Heath Taylor, sheriff of Russell County, said Houser returned to the house and vandalized it by pouring concrete down the plumbing and tampering with the natural gas lines, including the one that ran to a fireplace inside.
"If you'd turned it on it would have blown [flames] out," Taylor said.
He was arrested on arson charges in the 1980s when he was accused of hiring a man to set fire to office of a lawyer who represented pornographic movie theaters, according to the Ledger-Enquirer newspaper in Columbus.
The man was a police informant who turned in Houser, the paper said. It's unclear whether Houser was prosecuted.
In 2001, he lost his liquor license for Rusty's Pub in LaGrange, Georgia, for serving minors, according to public documents from the city.
In response, Houser hanged a flag with a swastika approximately the size of a bed sheet on the building where the pub operated, according to a local law enforcement official.
According to the official, Houser indicated it was in response to his belief that law enforcement, the city and the courts were behaving as if they were a Nazi regime.
"The people who used it -- the Nazis -- they did what they damn well pleased," Houser was quoted as saying in the LaGrange Daily News.
Houser kept the flag, which could be seen on one of the main streets in the city, on the building for several weeks.
He was arrested on allegations of public drunkenness and public intoxication outside Rusty's Pub in 1999, city documents said, but it's unknown whether he was prosecuted. In 2001, he was charged with probation violation in LaGrange.
Houser had a string of minor arrests, too. In Columbus alone he was arrested about 15 times between 1996 and 2011 on minor charges, such as no proof of auto insurance, no state tag, speeding and not having a business license, according to city police documents.
It all seems so distant from the Rusty Houser of earlier years, the one who seems to be portrayed in a profile on the professional networking site LinkedIn, the one who graduated from law school and who, according to the LinkedIn profile, owned restaurants and invested in real estate and hung out his shingle as a financial adviser.
He listed his skills as financial analysis, market forecast, public speaking and "God's business."
"It would be my pleasure," the owner of that LinkedIn profile wrote, "to assist you in financial matters or things more important."
An enterprising figure
Houser graduated from Faulkner Law School in Montgomery, Alabama
, in 1998, the university said Friday. It's not known whether he ever took the bar exam or practiced law. His name does not appear in a search of the Alabama State Bar.
According to the LinkedIn profile of a man with the same name and hometown and educational details of the shooting suspect, he'd previously graduated from Columbus State University, in his hometown of Columbus, in 1988 with a degree in accounting.
At age 23, according to the profile, Houser owned a bar in Columbus called the Peachtree Pub, before selling it in 1980.
He became involved in local politics, according to the Ledger-Enquirer.
Houser worked with others to defeat a school bond referendum and later ran for city tax commissioner -- the same post his father had held. But the younger Houser was accused of stealing an opponent's yard signs and withdrew from the election, the newspaper reported.
Former Columbus Mayor Bobby Peters told CNN that Houser was something of an articulate gadfly, always jumping into a local issue with passion. He often appeared on talk shows.
"He thought government was always operating behind the scenes and was not doing what we should be doing," Peters aid. "He was always challenging officials. ... He seemed to be wanting to be the voice for the citizens, the champion of the cause."
Peters said Houser's life seemed to go downhill beginning in 2002. That would have been after losing the liquor license at his tavern.
"If you look at the whole pattern he had all these dreams and they kept falling apart and it comes to a situation like this," Peters said.
The LinkedIn resume has a big gap until Houser again lists himself as the owner of the bar in LaGrange.
"In a small town one in the entertainment business had better be in with all crowds," his profile reads. "We successfully provided entertainment for all while maintaining an atmosphere worth a regular visit."
Another six-year gap is followed a brief dalliance in real estate investment in 2006.
A downward spiral
By 2008, it was clear that things were not going well for Houser.
That's when his wife, daughter, her fiancé and his parents sought a protective order in Georgia, saying they were worried about his "extreme erratic behavior" and "ominous as well as disturbing statements" that his daughter's impending marriage would not happen.
A day after one particularly jarring incident in April of that year -- he'd shown up at his daughter's work and then gone to the home of his wife's aunt and made threats there -- they obtained an order involuntarily committing him "because he was a danger to himself and others," according to the court filing.
Houser's wife was so worried about his mental state she had removed all guns and weapons from their home, the documents said.
According to the filing, Houser said he'd continue his "erratic as well as threatening behavior" once he got out of the hospital in an effort to stop his daughter's marriage.
Interactions with police
Houser popped up a few times in the years since. He appears to have posted hundreds of messages on political forums espousing anti-government and anti-media views as recently as 2013.
The Southern Poverty Law Center considered some of his online postings racist.
"He promoted the disproven racist theory that a connection exists between race and IQ," the SPLC website said.
Houser had a few interactions with authorities in Russell County, including a request for a permit to carry a concealed weapon that was denied because of the arson arrest and a 2005 domestic violence complaint that was never prosecuted, Sheriff Taylor said. But none of the issues foreshadowed Thursday's violent outburst.
"He has been a complainant on a few things and had a few traffic tickets, and that's all I have about him," Taylor said.
In February 2014, Houser legally purchased a handgun from a pawn shop in Phenix City, said police in Lafayette. It was the gun he used in the theater shooting.
Drew Griffin, a senior investigative correspondent for CNN, said law enforcement didn't necessarily drop the ball because Houser apparently didn't have any convictions for serious crimes.
"He just didn't show up on any of the instant background checks," Griffin said.
'He was going to get his life together'
Houser arrived in Lafayette in early July, taking up residence at a Motel 6, said Jim Craft, the Louisiana city's police chief. Why Houser chose the city or what he was doing there remains a mystery.
The only known link he had to Lafayette was an uncle who once lived there, but he died 35 years ago, police said.
There's some indication Houser was trying to turn things around, Louisiana State Police Col. Michael Edmonson told reporters.
"His mom had loaned him some money. He was going to get his life together," Edmonson said. Craft said Houser had talked to local businessmen about opening an oil-change shop.
Then came Thursday night. Police said Houser had swapped the license tag on his blue 1995 Lincoln Continental and parked it near the theater exit to the Grand Theatre 16, ready for a quick escape. He might have been drinking, Craft said, but there's no evidence of drug use.
Houser bought a ticket to the show just like everyone else, filed in and sat down. After the movie began, he stood up and began firing, police say.
He apparently tried to make his way out of the theater along with the people he'd just been shooting at, then saw police swarming in, Craft said. Houser then reloaded his .40-caliber handgun, returned to the theater and shot himself in the head as police pushed toward him.
Mindful of possible booby traps such as those set by Aurora, Colorado, theater shooter James Holmes three years ago, police blew out the windows of Houser's car and used a robot to blow open the trunk. While initially suspicious of some of the things they found inside, they found no explosives, authorities said.
Searching his hotel room, they found wigs and glasses -- "disguises, basically" -- leaving police yet one more thing to figure out.