The wrongful death lawsuit was filed in LaSalle County this month by the family of 37-year-old Douglas Hampton of Earlville.
Hampton was killed by a car after an officer left him along Route 34 west of Earlville early on July 11. Hampton was struck while walking the nine miles to his home.
The lawsuit contends the officer should have known Hampton was intoxicated and it could be dangerous to drop him off.
Illinois State Police are investigating the accident.