File Photo – Waukegan Police Department. | Photo: Willie Gillespie (@wgweather).

An 18-year-old who was shot “execution-style” and found on a sidewalk in Waukegan over the weekend is brain dead and on life support.

A Waukegan Fire Department ambulance came upon a subject who was down on a sidewalk and bleeding near Lewis Avenue and Lydia Street in Waukegan around 6:40 a.m. Sunday.

The ambulance was responding to an unrelated call at the time, according to fire department radio audio. The Waukegan Police Department was called to the scene.

Waukegan Deputy Police Chief Joe Florip said officers responded and learned the victim, described as an adult teenager, had been shot.

Two sources told Lake and McHenry County Scanner that the man was shot in the head.

A man was shot and critically wounded Sunday morning near the intersection of Lewis Avenue and Lydia Street in Waukegan. | Photo: Google Street View.

One source said that firefighters discovered the teen, who is 18 years old, with his hands tied behind his back.

The man was taken by ambulance to Advocate Condell Medical Center in Libertyville with serious injuries, Florip said.

The man, who resides in Waukegan, remains at the hospital on life support after doctors declared him brain dead, the sources said.

The Waukegan Police Department Criminal Investigations Division (CID) is leading the investigation, Florip said.

On Monday, police said no suspects were in custody yet. It is unknown if any suspects have been taken into custody since.

Anyone with information on the shooting is asked to call the Waukegan Police Department Criminal Investigations Division tip line at 847-360-9001.