In one of the most prolific “swat” cases ever prosecuted, a teenage “serial swatter” pleaded guilty Wednesday to making false 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. Justice Department in question. Filion faces a maximum sentence of five years in prison on each charge, federal prosecutors said.

From August 2022 through January, Filion made more than 375 attack and threat calls, including calls in which he claimed to have planted a bomb, threatened to detonate a bomb or commit mass murder, authorities said.

Court documents say he became a “serial trafficker” who made false accusations to keep law enforcement on the hook for profit and entertainment. Prosecutors said he turned swatting into a business by advertising his swatting services for a fee on social media.

Authorities said he was responsible for hundreds of assault cases across the country, including Maryland, Oklahoma, Pennsylvania, Louisiana, Washington and Texas.

Prosecutors said Filion was 16 when he made most of the searches, targeting high schools, universities, government officials, religious institutions and the homes of FBI agents.

“It caused deep fear and chaos,” Deputy Attorney General Lisa Monaco said in a statement.

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

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

At the Sanford incident, Filion claimed to have an illegally modified AR-15, a Glock 17 handgun, pipe bombs and Molotov cocktails, prosecutors said. Prosecutors said he would soon “carry out a mass shooting” and “kill everyone.”

“In his online post dated January 19, 2023, he claimed that his ‘first’ swing was ‘2 to 3 years ago’ and that he ‘decided to turn it into a business 6-9 months ago,'” prosecutors said. He stated that Filion advertised his services on social media.