Suffolk police say a man from Centereach is accused of stabbing an officer following a car crash in Patchogue.

Police say Jonathan Nunez, 25, was driving erratically with no headlights on South Ocean Avenue. They say an officer attempted to pull Nunez over, but Nunez crashed into another car at the intersection of South Ocean Avenue and Brook Street.

Authorities say Nunez left his car and engaged in a physical altercation with the officer in the yard of a home on South Ocean Avenue. They say Nunez stabbed the officer in the leg.

The altercation took place on the yard of Guillermo Sandoval, a former Marine. He says when he heard the officer calling for help, his training kicked in.

"I went upstairs, grabbed a belt and ran back out…started putting the tourniquet on him," Sandoval says. "At that time, other officers ran in and helped out."

Officials say retired NYPD officer JR Recupero also saw the struggle and ran to help. They say he stopped Nunez, who was trying to run. Suffolk police then took Nunez into custody.

The officer who was injured underwent surgery at the hospital and is now under close supervision.

Nunez was charged with aggravated assault upon a police officer, driving while intoxicated and resisting arrest.