In one of the most prolific “swatting” cases ever prosecuted, a teenage “serial swatter” pleaded guilty Wednesday to making hoax threats to schools, religious institutions and government officials about mass shootings and bombings across the country.

Alan Filion, 18, of Lancaster, California, pleaded guilty to four counts of making interstate threats, the Justice Department said. Filion faces a maximum penalty of five years in prison for each charge, federal prosecutors said.

From August 2022 to January, Filion made more than 375 swatting and threat calls, including calls in which he claimed to have put bombs in place, threatened to detonate bombs or carry out mass shootings, officials said.

He became a “serial swatter” — making false accusations to send law enforcement officers rushing to a location — for profit and entertainment, court documents said. Prosecutors said he turned swatting into a business by advertising his swatting services on social media for a fee.

Authorities said he was responsible for hundreds of swatting incidents throughout the country, including in Maryland, Oklahoma, Pennsylvania, Louisiana, Washington and Texas.

Filion was 16 when he made most of the calls that targeted high schools, colleges, government officials, religious establishments and the homes of FBI agents, prosecutors said.

“He caused profound fear and chaos,” Deputy Attorney General Lisa Monaco said in the statement.

Attorneys listed for Filion in court records could not immediately be reached for comment Wednesday afternoon.

In January 2023, Filion was extradited to Florida from California after having swatted a mosque months earlier in Sanford, Florida. Prosecutors said Filion targeted the Masjid Al Hayy Mosque and threatened to commit a mass shooting. The Seminole County Sheriff’s Office and the FBI tracked his posts on Telegram offering up his swatting services, as well as recordings of swatting calls.

In the incident in Sanford, Filion claimed to have an illegally modified AR-15, a Glock 17 pistol, pipe bombs and Molotov cocktails, prosecutors said. He said he was going to imminently “commit a mass shooting” and “kill everyone," prosecutors said.

“He claimed in a Jan. 19, 2023, online post that his ‘first’ swatting was like ‘2 to 3 years ago’ and that ‘6-9 months ago [he] decided to turn it into a business,’" prosecutors said, noting Filion posted on social media advertising his services.