OHP spokesman Capt. George Brown said over the weekend Robinson, who has been with the patrol for more than 16 years, approached two armed men at Best Budget Inn near Admiral and Sheridan around 1 a.m. Sunday.
Brown said Robinson identified himself, then something happened to make him feel threatened. Robinson then opened fire, killing 25-year-old Michael Troy Swatosh.
The other man fled the scene.
OHP spokesman Capt. George Brown says no other details will be released while the investigation is ongoing.