There was no known motive to why Stephen Paddock opened fire on a crowd of 22,000 people from his hotel room at the Mandalay Bay in Las Vegas, but that didn’t stop people from speculating. The gunman conducted the deadliest shooting on U.S. soil in modern history. As of Wednesday, his infamous killing spree left 59 people dead and more than 500 injured — but no one had a reason why.

With so many unanswered questions, Twitter users took it upon themselves to provide a possible motive. Paddock was not labeled as a terrorist, despite outcry from social media users for him to be called one.

The Islamic militant group also known as ISIS took responsibility for Paddock’s attempt, though the FBI said the ISIS was not involved.

One theory was that he was a liberal who was apparently targeting Trump supporters.

Paddock, 66, and his girlfriend, Marilou Danley, used to live in Reno in 2012. Their former neighbor, Susan Page, 68, described the mass murderer as a “reclusive weirdo” to The Sun Tuesday.

“He would keep his face down, avoid all conversation and was just very unfriendly and strange,” Page said. “I never heard music, conversation and never once saw them have friends over.”

Page was stunned when she discovered her former neighbor was responsible for the deadly attack. “I barely slept last night thinking about this evil man living next door with a house full of guns,” she said. “It could have been any of us he unleashed this horror on. It's just too much to even think about.”

“It’s hard to believe in this quiet caring community a monster was living next door,” she added to The Sun. “But now when we think about it he was such a reclusive weirdo, so maybe it isn’t that surprising after all. I lived next door to him and his girlfriend and never once got as much as a smile out of him. They had barely any furniture in the house and nothing in the yard, the shades were always down and it was like they were not even living there.”

Danley is a “person of internet,” but her sister, who did not want to be identified, told CNN affiliate Seven Network Australia, Danley was not involved.

“I know that she don't know anything as well, like us. She was sent away. She was sent away so that she will be not there to interfere with what he's planning,” the unidentified sister said. “In that sense, I thank him for sparing my sister's life,” she said, adding Danley was “really in love with Steve.”

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