Massachusetts authorities say undercover state troopers approached an SUV in Springfield shortly before the driver sped off and caused a crash that killed four people.
A spokesman for Hampden District Attorney Anthony Gulluni told The Republican newspaper on Friday that troopers parked behind the SUV, turned on their unmarked cruiser's emergency lights, got out and approached the SUV Tuesday night.
The spokesman, James Leydon, said the SUV then sped away. The troopers were patrolling the streets as part of a gang unit. Leydon said the troopers got back in their cruiser, turned off the emergency lights and came upon the crash site a short time later.
The SUV was stolen in Milford, Connecticut, earlier this month.
All four people who died were from Springfield, including three high school seniors.