CHICAGO (CBS) — An Arlington Heights man has been charged with driving under the influence in a fatal crash on the Eisenhower Expressway earlier this week.

Illinois State Police said 35-year-old Matthew Graff was driving a 1993 Chevrolet motor home in the westbound lanes of the Eisenhower Sunday afternoon, when he slammed into the back of a 2005 Nissan sedan that had stopped on the right shoulder near Mannheim Road.

matthew graff Man Charged With DUI In Fatal Eisenhower Expressway Crash

Matthew Graff is charged with two counts of aggravated DUI, in a crash that killed a 34-year-old man and seriously injured a 42-year-old woman on the Eisenhower Expressway on May 6, 2018. (Credit: Illinois State Police)

The driver of the Nissan, 34-year-old Eduardo Moreno, of Berwyn, was taken to Loyola University Medical Center, where he was pronounced dead. Moreno’s passenger, a 42-year-old woman, was seriously injured, but expected to survive.

Police said Graff was taken to Elmhurst Hospital, but his injuries were not life-threatening.

Investigators said Tuesday they believe drugs were a factor in the crash. Graff has been charged with two felony counts of aggravated DUI. Police did not say whether the charges involved the use of drugs or alcohol.