Wisconsin and Illinois authorities are now teaming up to search for a murder suspect.
Early Sunday morning, police said, Kody Walsh was driving from Rockford toward Wisconsin on Interstate 90 when he shot and killed his female passenger near the tollway south of Beloit.
The victim is Lori Daniels, 36, of Janesville, according to the Winnebago County Coroner's Office.
A witness called police, which led to a high-speed chase back to Rockford.
Police said Walsh, 22, crashed his SUV, left it – with Daniels still inside – and ran away, all the time firing shots at officers. Police said they did not return fire.
"I think in this type of crime, anybody should be concerned, and if they do know him or they do see him, they should contact police right away and let them know his whereabouts and not try to confront him themselves," said Capt. Jim Winters of the Illinois State Police.
Illinois state police have now taken over the investigation.