An off-duty New York City policeman is credited with alerting Wisconsin law enforcers about online threats to kill an officer.

New York’s Daily News says Officer Gregory Santora contacted police in Madison, Wisconsin after spotting a Periscope video on Saturday.

Santora says he was “scared” to see a crying man arming himself and “implying that he was going to live-stream the shooting” of police officers.

The suspect said he was going to the place where police killed a man last year and shoot the first officer he saw.

Instead, he encountered an officer who was expecting him and arrested him.

Wisconsin’s Dane County sheriff’s office said Monday that Raynarldo Glenn was awaiting a court appearance. There was no immediate information on an attorney who could comment on his behalf.

(AP)