A man who left threatening messages to a staffer at his former Hudson Valley school is accused of owning 19 deadly weapons, high-capacity magazines, a bump stock, knives and more.

On Saturday, the Clarkstown Police Department received a report of a suspicious incident, possibly involving a threat to a staff member at the Summit School in Upper Nyack.

Responding officers interviewed a 45-year-old school employee who told police he received six messages on the school’s voicemail system from a former student.

The former student, later identified as 32-year-old Robert Csak of Lindenhurst, left threatening messages on the voicemail system, police say.

The staff member told police he was concerned for the safety of the students and staff and the well-being of the caller.

Clarkstown police contacted the Suffolk County Police Department after they traced the calls back to Csak's Long Island's home through the school's caller ID system, according to the New York Daily News.

During a search of Csak's home, officers recovered 19 firearms, a silencer, more than 200 high-capacity magazines, a Tommy gun, night vision goggles, bulletproof vests, gas masks, knives, asps and a bump stock, police say.

“This is another example of schools identifying a potential problem and law enforcement agencies leaving no stone unturned to ensure that the safety of students and staff is paramount," Clarkstown Police Chief Raymond McCullagh said.

Csak was arrested Lindenhurst on multiple weapons charges.

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