Police say they were called to the Holiday Inn Express in the 600-block of Lakehurst Road for a report of a person with a gun.
When police arrived around 8:30 p.m. Wednesday, they say a man pulled out a handgun.
An officer fired one shot at the man, killing him.
The Lake County Major Crimes Task Force is investigating.
Lake County Coroner Artis Yancey has identified the man as 34-year-old John Corcoran of Waukegan. No officers were injured in the incident.
The Associated Press contributed to this report.