A man who was committed to a mental institution after authorities found plans to commit a school shooting was accused of making false statements to acquire firearms, prosecutors said Friday.

Clayton Girard, 27, was arrested Oct. 22 in Santa Clara for lying about his mental health history when he bought 11 firearms, including AR-style rifles, semiautomatic pistols and shotguns, according to the U.S. Attorney’s Office for Northern California.

In statements required for firearms purchases from federally licensed gun dealers, Girard repeatedly answered that he had never been committed to a mental institution, prosecutors said.

A federal indictment alleges that in 2017, Girard was involuntarily committed to a mental institution in New York after authorities discovered his journal, which included detailed plans to commit a mass shooting at his school and to abduct and murder a specific acquaintance.

“An individual who threatened former classmates, authored a manifesto describing horrific acts of violence, and subsequently acquired numerous firearms presents precisely the kind of public safety threat that demands a quick federal response, which is exactly what occurred here,” U.S. Attorney Craig H. Missakian said in a press release.

If convicted, Girard faces a maximum sentence of 10 years in prison and a fine of $250,000 for each violation of federal law.