A North Carolina man was arrested Sunday after he walked into a popular pizza restaurant in Northwest Washington carrying an assault rifle and fired one or more shots, D.C. police said. The man told police he had come to the restaurant to “self-investigate” a false election-related conspiracy theory involving Hillary Clinton that spread online during her presidential campaign.

The incident caused panic, with several businesses going into lockdown as police swarmed the neighborhood after receiving the call shortly before 3 p.m.

Police said 28-year-old Edgar Maddison Welch, of Salisbury, N.C., walked in the front door of Comet Ping Pong and pointed a firearm in the direction of a restaurant employee. The employee was able to flee and notify police. Police said Welch proceeded to discharge the rifle inside the restaurant; they think that all other occupants had fled when Welch began shooting.

Welch has been charged with assault with a dangerous weapon. Police said there were no reported injuries.

Interim D.C. Police Chief Peter Newsham said police arrived on the scene minutes after the first call, set up a perimeter and safely arrested Welch about 45 minutes after he entered the restaurant.

A D.C. police report made public Monday says Welch had been armed with an AR-15 assault-style rifle. The report also says police seized a Colt .38 caliber handgun and a shotgun. One of those weapons was found inside the restaurant; the other in the suspect’s car. Police did not specify the locations.

The police report also describes Welch’s arrest. Police said he surrendered shortly after officers surrounded the pizza shop and emerged with his hands raised above his head.

The report says in addition to the weapons, police seized a folding knife, a T-shirt, a hooded sweatshirt and denim blue jeans.

Vivek Jain, of Potomac, Md., was eating lunch inside Banana Leaf, a nearby Indian restaurant, when Comet patrons came rushing inside. He said Banana Leaf was locked down for about 90 minutes.

“A bunch of people ran in from Comet and said a man walked in with a gun,” Jain said.

About 45 minutes later, he said, he saw a man walking backward out into the street with his hands in the air.

“He laid down on Connecticut Avenue and he was immediately picked up by the police and taken away,” he said.

[Fake news makes Comet Ping Pong a target for conspiracy theories]

The popular family restaurant, near Connecticut and Nebraska avenues NW in the Chevy Chase neighborhood, was swept up in the onslaught of fake news and conspiracy theories that were prevalent during the presidential campaign. The restaurant, its owner, staff and nearby businesses have been attacked on social media and received death threats.