Fake news became all too real over the weekend after a North Carolina man entered a Washington pizzeria with an assault rifle in an attempt to "self-investigate" a false but persistent conspiracy theory about Hillary Clinton.

The baseless theory is that the business was a front for a child sex ring run by Hillary Clinton and her campaign manager.

Edgar Maddison Welch, a 28-year-old man from Salisbury, N.C., walked into Comet Ping Pong in the capital around 3 p.m. on Dec. 4. Police said pointed his gun at a worker, who fled, and then Welch started firing the rifle inside the restaurant, the Washington Post reported.

Patrons and other employees also ran away, police said. The suspect, who allegedly had an AR-15-style rifle and other weapons, surrendered to police and was charged with assault with a dangerous weapon. There were no reported injuries.

Welch told police he was there to check into unfounded rumors that Comet Ping Pong, which hosts children’s parties and occasionally small concerts, was actually part of what the Internet has dubbed "Pizzagate."

D.C. police described Pizzagate as "a fictitious online conspiracy theory" in its press release for Welch’s arrest. But where did this theory come from?

Pizzagate's origins

The conspiracy theory spread through viral emails, discussion threads and social media in the weeks leading up to Election Day.

The rumor first began after WikiLeaks released Clinton campaign manager John Podesta’s emails.

Users at the online forum 4Chan noticed Podesta corresponded with Comet Ping Pong pizzeria owner James Alefantis, discussing a potential Clinton fundraiser.

Buzzfeed reported that the idea of a pedophilia ring masterminded by Clinton and her allies started with an Oct. 30 tweet by a reputed white supremacist Twitter account that in turn cited a Facebook user’s status:

Rumors stirring in the NYPD that Huma's emails point to a pedophila ring and @HillaryClinton is at the center. #GoHillary #PodestaEmails23 pic.twitter.com/gkEH5oL269 — David Goldberg (@DavidGoldbergNY) October 30, 2016

From there, various conspiracy theory and fake news sites began spinning out versions of the elaborate but unproven story. (A popular Reddit post detailing the theory has since been removed.)

The gist of the fake theory is that Podesta’s repeated use of the word "pizza" in emails detailed in the WikiLeaks release was actually a code word for pedophilia. Comet Ping Pong was allegedly the base for secret rooms in which Clinton and her allies kidnapped and imprisoned children to be sexually abused, tortured or even sacrificed in the name of Satan. Democrats in both Clinton’s campaign and the federal government have colluded to hide the abuse, the theory alleges.

Some sites have claimed that various details about the pizzeria "prove" that Comet Ping Pong uses coded language and symbols to advertise its secret business to pedophiles. Random pictures of children have been appropriated to falsely illustrate the fake ring’s so-called victims.

The story has circulated on various fake news sites for weeks, although some have since been taken down.

There has been no evidence that any such sex ring exists. But that hasn’t stopped conspiracy theorists from harassing Comet Ping Pong, its employees and even neighboring businesses.

Comet Ping Pong

Let’s go back to Alefantis, who said he has never met Clinton but supported her presidential bid. The 42-year-old Alefantis was once in a relationship with David Brock, a former conservative commentator who now runs the liberal site Media Matters For America.

The New York Times reported in early November that Alefantis noticed a sharp uptick in his social media traffic in the weeks leading up to the election. People he didn’t know began to send death threats and vulgar messages. Employees and their families also were threatened via social media and text messages.

Alefantis filed a police report about the harassment, and authorities have had to intervene before. One man who believed the fake theory posted video from inside the restaurant and was told by police to leave, the Times reported.

After Welch fired his weapon inside the popular restaurant, Alefantis blamed the prevalence of fake news and those that spread it for the troubles at Comet Ping Pong.

"What happened today demonstrates that promoting false and reckless conspiracy theories comes with consequences," he said in a Facebook post. "I hope that those involved in fanning these flames will take a moment to contemplate what happened here today, and stop promoting these falsehoods right away."

Internet response

Even as traditional news outlets have reported on Pizzagate, supporters of the wild theories have argued that attention from the mainstream is only proof that media is in on the coverup.

The hashtag #Pizzagate filled Twitter with users doubting the coverage of Welch’s activities at Comet Ping Pong, including media denials of Pizzagate’s validity.

One notable conspiracy theorist is Michael Flynn Jr., son of incoming national security adviser and retired U.S. Army Lt. Gen. Michael Flynn. The elder Flynn has previously shown support to other conspiracy theories that Clinton is tied up with alleged money laundering and sex crimes unrelated to Comet Ping Pong.

On Sunday the younger Flynn tweeted he was skeptical of reports that Pizzagate wasn’t real.

Until #Pizzagate proven to be false, it'll remain a story. The left seems to forget #PodestaEmails and the many "coincidences" tied to it. https://t.co/8HA9y30Yfp — Michael G Flynn🇺🇸 (@mflynnJR) December 5, 2016

The tweet included another tweet from Citizens For Trump special projects director Jack Posobiec alleging Washington D.C. Police Chief Peter Newsham found no connection between Welch and Pizzagate.

We could find no evidence that Newsham said that, only that he initially told the Post the incident was likely not "terrorist related."

According to the official press release from D.C. police, Welch himself admitted he was there because of the conspiracy theory: "During a post arrest interview this evening, the suspect revealed that he came to the establishment to self-investigate ‘Pizza Gate.’ "

Correction: An earlier version of this story incorrectly referred to Welch's weapon as automatic.