A Massachusetts man is suspected of stockpiling weapons and ammunition in order to carry out attacks on police, a mosque, or both.

The FBI arrested Joseph Garguilo of Holliston, Mass. on Saturday after raiding his home and finding the parts for an AR-15 rifle, ammunition, chemicals that could make explosives when combined, and threatening messages. According to the Massachusetts U.S. Attorney’s office, there was already a restraining order out against Garguilo who is prohibited from possessing weapons under the order. He’s facing charges that he violated it.

The threatening letters and messages said to be discovered at Garguilo’s residence included messages about harming Muslims. The FBI also alleges the man had threatened to “chain a mosque closed and burn it down” as well as “plant a bomb in police station…and kill as many homeland security officers as he can before they kill him.” Garguilo also is believed to have said he wanted to harm President Obama.

The U.S. Attorney’s office says his actions carry a maximum penalty of 10 years in prison and a $250,000 fine.

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