KALAMAZOO, Mich. — Authorities trying to piece together an hours-long weekend rampage that left six people dead in western Michigan said they are looking into a report that the suspect picked up at least one fare for a ride-hailing service between shootings.

Jason Dalton, a 45-year-old Uber driver and former insurance adjuster who police said had no criminal record, was arrested in connection with the shootings after a massive manhunt and was expected to be arraigned today. Authorities could not say what they believed motivated him to target victims with no apparent connection to him or to each other in the Saturday night shootings.

“How do you go and tell the families of these victims that they weren’t targeted for any reason other than they were there to be a target?” Kalamazoo County Prosecutor Jeff Getting said at a Sunday news conference.

Kalamazoo County Undersheriff Paul Matyas described a terrifying series of attacks that began about 6 p.m. Saturday outside the Meadows apartment complex on the eastern edge of Kalamazoo County, where a woman was shot multiple times. She was expected to survive.