Nassau County Officer Michael Califano had pulled a vehicle over near exit 39 in Old Westbury for having insufficient lights and was sitting in his car when it was struck from behind shortly before 11 p.m. Friday, authorities said.
The impact propelled the cruiser under a stopped box truck, while the flatbed mounted the police vehicle's roof. It took rescuers a half-hour to remove the roof and free the severely injured officer, who was declared dead about an hour later at a hospital.
Califano was 44 and a member of the police Highway Patrol Unit. He had been on the force for 12 years, the department said.
The flatbed truck driver was charged Saturday in Califano's death.
John Kaley, 25, of New Britain, Conn., was arraigned in Hempstead District Court on charges of criminally negligent homicide, third-degree assault and failing to move over for an emergency vehicle, police said.
Represented by a Legal Aid attorney, he pleaded not guilty and is being held without bail at Suffolk County Jail until his court appearance Feb. 8, according to the court clerk's office.
Three other people suffered less serious injuries in the wreck, which closed part of the expressway for hours overnight, said Nassau County police Lt. Kevin Smith.
The injured included two people who were in the box truck and a female passenger in the flatbed truck. All were being treated at a hospital.
Nassau County Executive Edward Mangano ordered flags at Nassau County buildings to be flown at half-staff.
He said in a statement that he has known the Califano family for years, "and my thoughts and prayers go out to them, their friends and fellow police officers during this sad time."