Police said officers responded to a domestic disturbance call at approximately 1:30 a.m. at a home in the 100 block of Marimac Lane.
Officers opened fire after the man threatened them with a rifle inside the home's garage.
The man was pronounced dead at the scene. He was identified Monday as 34-year-old Randy Rausch, of Vernon Hills, according to the Lake County coroner.
The incident is under investigation.