A Winnebago County Sheriff's detective may have spotted murder suspect Terence Doddy.
Doddy is wanted for two murders that happened this week.
His co-worker Todd Hansmeier was killed in Rockford on Monday.
Police say Doddy beat him to death and then tried to burn his body inside an office building.
The next day, Tonya Bargman was murdered by a washroom at the Willow Creek rest stop on I-39.
Hansmeier's car was abandoned there.
But Bargman's car, a gray 2013 Nissan Altima with Illinois plate BARGMN2 and a decal that says “Illini Nissan” on the lower rear bumper.
Investigators say a detective spotted Bargman's car Thursday night, north of Rockford.
Police responded by searching subdivisions, forest preserves, and a quarry.
They also released a picture of Doddy with a shopping cart that may have held a blue dome-style camping tent.
Police issued nationwide alerts on Doddy.
They're especially warning anyone on the road during Independence Day weekend.