The brazen attack in Philadelphia happened around 4 p.m. on November 25 on the 4500 block of Frankford Avenue.
Surveillance video shows the male suspect walking up to the 37-year-old PPA officer from behind and shooting him in the ear and shoulder.
According to investigators, Philadelphia police received information from the New York City Police Department that the man seen in the video may have also shot a Sunoco gas station employee in the Bronx on November 22.
SEE ALSO: Philadelphia Parking Authority officer shot while on duty
Philadelphia Parking Authority officer shot while on duty
That employee was shot in the head, police said.
The PPA officer, who has been identified as Timothy McKenzie, is assigned to the Frankford neighborhood and is well-known in the community.
McKenzie is expected to make a full recovery.
The suspect is described as a man who is about 5 feet 9 inches to 6 feet tall, with a thin build. He was seen wearing a navy blue hooded sweatshirt, green cargo pants, black mask, gloves and black boots.
The suspect should be considered armed and dangerous.
The City of Philadelphia and The Philadelphia Parking Authority each have offered $10,000 for a total of $20,000 for information that leads to an arrest and conviction of the man in the photos.
Anyone with information on the suspect is asked to call police at 215-686-TIPS.