(CBS) — An off-duty Waukegan police officer was killed in a crash early Saturday in Gurnee.

WBBM Newsradio’s Steve Miller reports Waukegan Police Officer Jason Mueller was not wearing a seat belt when his car crossed over a median in Gurnee early Saturday, and hit a utility pole.

An autopsy Monday determined Mueller, 27, died of head injuries.

Gurnee Deputy Police Chief Saundra Campbell said Mueller was the only one in the car as he was driving on Washington Street.

“He was traveling westbound. He went into the median, traveled south across the eastbound lanes and hit a pole… approximately 20 feet off the roadway – a Commonwealth Edison pole,” Campbell said.

Toxicology tests are not back, the coroner’s office says.

Mueller had served on the Waukegan Police Department for about 10 months. He previously had served as a U.S. Army Ranger, and had two tours of active combat duty in Afghanistan and one tour in Iraq.

He is survived by his wife and daughter.

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