DETROIT — A Michigan teen with antisemitic views and a desire to mimic past mass shootings had a plan to kill and might have been targeting a synagogue, federal officials said.

Seann Patrick Pietila, 19, was arrested Friday and charged with transmitting a communication containing a threat to injure another, the U.S. Attorney’s Office said.

A search of Pietila’s home turned up ammunition, magazines, a shotgun, a rifle, a pistol, knives and other firearm accessories, along with a Nazi flag, gas masks and military manuals, officials said.

Note found with date, list of equipment

Authorities said they found a note in Pietila’s phone with the name of an East Lansing synagogue, the date March 15, 2024, and a list of equipment.

“Equipment: hand-made pipe bombs, molotovs, Two Stag-15s, 12 guage shotgun and two back up Glock 18s AND a Akm full auto conversion,” the note reads, according to officials.

Pietila “evinced a neo-Nazi ideology, antisemitism, glorification of past mass shooters, and a desire and intent to mimic past mass shooters or mass casualty events,” U.S. Attorney for the Western District of Michigan Mark Totten said in a news release.

FBI received report of threats made on Instagram

In a court filing, an FBI agent said the agency received a report of threatening online communications on Instagram on Tuesday. Meta, the company that owns Instagram and Facebook, provided agents with messages sent by an account investigators found was Pietila’s.

Agents found social media messages from Pietila and learned that he attended Lansing’s Eastern High School during the 2020-21 school year, according the agent’s filing.

Pietila was detained when the FBI executed a search warrant at his home on Friday, according to the court filing.

He told investigators he had moved to Pickford, Michigan, a week prior and previously lived with his mother in East Lansing, near the Michigan State University campus, the filing said. He indicated he was “most likely” in East Lansing when he communicated threats, according to the document.