WAUKEGAN — A man who drove head-on into an Illinois State Police trooper's squad car last month was drunk, according to authorities.

Dan Davies and the state trooper, Macomb-area native Gerald Ellis, were killed in the collision March 30 north of Chicago.

Toxicology results revealed Davies had a blood-alcohol level of .169 at the time of the crash, Lake County Coroner Howard Cooper said Friday. The legal limit in Illinois is .08.

Davies, 44, of Calumet City also had in his system THC, which is found in cannabis.

"We don't know when he necessarily took that," Cooper said. "He could have taken it the day before. It does linger."

An anti-nausea medicine, promethazine, also was reported. Promethazine is available by prescription, although Cooper said he didn't know if it had been prescribed to Davies.

Cooper received the toxicology results earlier this week. Alcohol was the major red flag, according to the coroner.

The crash took place about 3:30 a.m. March 30, a Saturday, in the westbound lanes of Interstate 94 in Green Oaks, east of Libertyville.

The 36-year-old Ellis, an 11-year State Police veteran, resided in Antioch with his wife, Stacy, and their daughters, aged 7 and 5. Antioch is in Lake County, along the Wisconsin border.

But Ellis was originally from rural Colchester, located a few miles west of Macomb in McDonough County. He was a 2002 graduate of old Colchester High School.

Reports earlier this month indicated the Illinois Secretary of State's office had no record of Davies ever having a driver's license. He had been arrested twice for drunken driving.

Various law-enforcement and public-safety organizations still are investigating the circumstances of the crash. Cooper suggested more information might be available in about a month.

"The only thing we do know is he got on the highway going the wrong way," Cooper said.

Nick Vlahos can be reached at 686-3285 or nvlahos@pjstar.com. Follow him on Twitter @VlahosNick.