Sean Morrison, 46, of Lake Ronkonkoma, was driving a 2001 Volkswagen northbound on Holbrook Road when his vehicle struck a female pedestrian who was standing in the roadway at 9:12 p.m.
Amanda Giardina, 29, of Holbrook was transported to Stony Brook University Hospital via a firedepartment ambulance where she is being treated for multiple fractures. Giardina is listed in seriouscondition. Morrison was uninjured.
The Volkswagen was impounded for a safety check, and the investigation is continuing.
Detectives are asking anyone with information on the crash to contact the Sixth Squad at 631-854-8652 or call Crime Stoppers at 1-800-220-TIPS.