A 19-year-old Michigan man who was arrested earlier this month on allegations that he used social media to discuss plans to attack a synagogue was indicted Wednesday by a federal grand jury.

Seann Patrick Pietila was indicted on two counts of threatening communications in interstate commerce, and one count of threat to kill or injure by means of fire, according to court documents.

The suspect used Instagram to discuss his plans to “commit acts of violence to kill other people,” the Justice Department said in a news release, adding that he posted Instagram messages which were antisemitic, expressed neo-Nazi ideology and praised mass shooters.

Pietila was arrested by FBI agents on June 16, three days after federal investigators were alerted to his online activity. According to previous court documents, following his arrest, investigators searched his phone and found a note referencing Shaarey Zedek, a synagogue in East Lansing, Michigan.

They also found the date, March 15, 2024, which was an apparent reference to the deadly New Zealand mass shooting that occurred on March 15, 2019, court documents said. Also discovered on the phone was a list of equipment, including pipe bombs, Molotov cocktails and firearms.

When investigators searched his home, they found a 12-gauge shotgun, ammunition, several knives, tactical vests and a Nazi flag, court documents stated.

If convicted as charged, he faces a maximum sentence of 10 years in prison for the charge of threatening communications in interstate commerce, and five years for the charge of threat to kill or injure by means of fire.

“No one should face violent threats because of their race, ethnicity, religion, or any other status,” Mark Totten, U.S. attorney for the Western District of Michigan, said in a statement. “We have seen a rise in antisemitism across the nation and here in Michigan, and my office is committed to using all our powers to protect the public and ensure accountability.”

In a report released in March, the Anti-Defamation League found that the number of antisemitic incidents in the U.S. rose 36% in 2022 compared to the year before.

Earlier this month, a 50-year-old man was found guilty on 63 criminal counts in a 2018 shooting at a Pittsburgh synagogue which killed 11 people, the deadliest antisemitic attack in U.S. history. 

— Cara Tabachnick, Robert Legare and Jordan Freiman contributed to this report.