BOSTON (AP) — A Massachusetts man has been charged with posting on an FBI website that he planned to kill President Barack Obama.

Andrew O’Keefe, of Mansfield, has been charged with a felony count of posting an online threat against the president.

According to court documents, when law enforcement officers tried to interview O’Keefe regarding the May 13 posting, he refused to speak with officers outside his home. Authorities say more than 100 weapons were found at his home and in his vehicle, including swords, double-edged knives, hatchets and spears.

The 28-year-old O’Keefe is expected to make his initial appearance Monday in U.S. District Court in Boston. He faces a maximum sentence of five years in prison if convicted.

It wasn’t immediately clear if O’Keefe has an attorney to comment on the charges.