Port St. Lucie, Fla. ? Police on Friday found what appeared to be a family of four gunned down overnight along an isolated stretch of highway: a woman clutching two children in a forlorn effort to protect them, with a man’s body nearby.

Investigators believe the victims’ vehicle had pulled to the side of Florida’s Turnpike before someone else in the vehicle shot them and drove away sometime between 1:30 a.m. and 3 a.m., Sheriff Ken Mascara said.

The sheriff would not say whether investigators knew of a motive or had any suspects.

A passer-by spotted the bodies about 8 a.m. in Port St. Lucie and alerted the Florida Highway Patrol. The bodies were in a grassy area near a golf club, several miles from the nearest rest stop.