MINEOLA, N.Y. (CBSNewYork/AP) — The partner of a Nassau County police officer killed during a traffic stop in October 2012 testified Friday at the murder trial of the man charged with firing the fatal shot.

Nassau County Emergency Services Officer Clarence Hudson pointed directly at defendant Darrell Fuller and identified him as the one who killed his partner, Officer Arthur Lopez.

“I saw the defendant fumbling near his waist then I heard a pop,” Hudson said. “It wasn’t that loud at the time. I didn’t really associate it with a gunshot. I didn’t know what it was.”

Hudson testified that just a moment later Lopez turned back toward the Emergency Services response truck that Hudson was driving and said, “I’m shot.” The officer then fell toward the truck and onto the ground, Hudson said.

Hudson can be heard on radio recordings that were released Thursday calling for an ambulance following the shooting .

“My partner’s down, get an ambulance here forthwith. Subject took off. Gunshot wound,” he said.

Hudson said his partner never said another word; Lopez was declared dead at a nearby hospital.

Fuller, a 34-year-old ex-convict from Queens, pleaded not guilty to first-degree murder.

Hudson testified that he and Lopez were patrolling near the Nassau-Queens border when they suspected a car driven by Fuller had been in a collision. He said the rear bumper on Fuller’s Honda appeared to be dragging near the ground and at least one tire was blown out.

The officers pursued him as he entered the Cross Island Parkway, headed south. Hudson said Fuller did not stop when they flashed their lights and siren and later motioned to him to pull over.

The officers followed as Fuller left the highway at the next exit. Fuller was out of his vehicle, Hudson said, when Lopez jumped out of the ESU truck and approached him armed with a stun gun. He said his partner never took his service weapon out of his holster.

After the 29-year-old Lopez was shot, Fuller then allegedly shot and killed Raymond Facey, 58, who was parked nearby making a cellphone call to his daughter. Fuller fled the scene and was arrested hours later.

A friend of Fuller’s is facing charges in Queens for allegedly shooting Fuller twice with graze wounds to make it appear as if the alleged gunman was a victim, and not the perpetrator, of the carnage.

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