YAPHANK, N.Y. — A Long Island man was arrested on weapons charges on Thursday after police officers found assault rifles, bomb-making instructions, over $40,000 in cash and Nazi paraphernalia in his house, the authorities said.

The man, Edward Perkowski, 29, of Mount Sinai, also faces drug charges after the police recovered marijuana and mushrooms during the search.

Mr. Perkowski’s brother, Sean, 25, who also lives in the home, was arrested on an unrelated outstanding bench warrant, the police said.