CHICAGO (AP) — Authorities in suburban Chicago are investigating the possibility that a man suspected in the beating death of his girlfriend intentionally swerved into oncoming traffic, killing himself and the driver of another vehicle.

Lake County Sheriff’s Deputy Chief Chris Covelli says it was a “strong theory” of investigators that the man killed his girlfriend with a blunt object in his home in the Lake County community of Lindenhurst and then killed himself in Monday’s head-on crash.

Covelli says the man was the only suspect in the slaying of 25-year-old Kelly Hedmark, of Algonquin. Her body was found by police Tuesday inside the home in Lindenhurst after her family learned of the boyfriend’s crash and reported her missing.