The Friday shooting of a police officer in New Kensington, Pennsylvania, has led to the FBI, the U.S. Marshals Service and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives to jointly offer a $40,000 reward for information about the shooting.

Rookie police officer Brian Shaw was fatally shot during a traffic stop in New Kensington, about 18 miles from Pittsburgh. Witnesses say that about 7 to 8 shots were fired, and one witness said that “Whichever one was shooting knew how to use a gun. It was quick.”

Shaw was pronounced dead shortly after he was taken to a local hospital.

Police have also found a .40 caliber slug from the porch of one of the witnesses. Footage from a CCTV camera at the witness’s home was unclear because it was nighttime, and has been taken in for enhancement.

No information is being revealed other than the fact that investigators know why the suspect was pulled over.

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