The collision occurred at approximately 12:55 p.m. on Tuesday, February 3rd, at the intersection of William Floyd Parkway and Ridgewood Drive.
Police said Sgt. Wayne Kelly, 46, was on duty and operating an unmarked 2017 Chevrolet Impala southbound on William Floyd Parkway when the crash occurred.
At the same time, a northbound 2008 Honda Odyssey was attempting to make a left turn onto westbound Ridgewood Drive.
Investigators said the Honda struck the Impala during the turn.
Emergency personnel responded to the scene and provided medical assistance. Kelly was transported by ambulance to Stony Brook University Hospital with serious but non-life-threatening injuries, police said.
The driver of the Honda was identified as Cristian Guartatanga Carchipulla, 40, of Shirley. Police said Carchipulla was taken to a local hospital and treated for minor injuries.
Detectives from the Suffolk County Police Major Case Unit were called to the scene and are investigating the circumstances leading up to the crash.
Authorities did not immediately release additional details about road conditions or whether any summonses were issued.
Both vehicles were impounded for a safety check, which is standard procedure in serious crashes involving injury, police said.
The intersection remained under investigation for a period of time Tuesday as detectives gathered evidence and spoke with witnesses.
Police are asking anyone who may have seen the crash or has information that could assist investigators to contact the Major Case Unit at 631-852-6555.
The investigation remains ongoing, and additional information is expected to be released as detectives continue to determine the cause of the collision.