An off-duty Chicago police officer was shot in the head early Wednesday, just two blocks from CPD headquarters in Bronzeville.

The 25-year-old male officer — on the job two years and assigned to the Gresham District on the South Side — was driving with a female in the 200 block of East 37th Street around 1:38 a.m. when they noticed a black Toyota following them, CPD Supt. Eddie Johnson said Thursday morning.

The female became nervous and called 911, Johnson said. Soon after, someone in the Toyota opened fire on the rear windshield of the officer’s vehicle, striking him in the back of the head. The officer did not return fire and crashed his SUV into a nearby tree a short time later.

About 20 rounds were fired, according to police. The female, who was unharmed, ran off at the sound of gunfire, was quickly located and is cooperating with detectives. Nearby officers heard the shots and immediately responded to the scene.

“This ain’t TV,” Johnson told reporters at a news conference Wednesday. “This is real life stuff.”

The officer was taken to University of Chicago Medical Center for emergency surgery, Johnson said, adding that he was responding to stimuli and gave a thumbs-up after surgery, though he remained in critical condition late Wednesday morning.

“I have no doubt that this officer has seen his share of gun violence while working in the 6th District,” Johnson said. “Today the same violence has left one of our own clinging to life.”

The wounded officer’s father is a recently retired CPD officer, said Johnson, who knows the father from their time together in the Gresham District. Johnson’s son also works in the district and knows the wounded officer.

“This incident has a significant impact on me personally,” Johnson said. “This tragic event reminds us that Chicago police officers are not immune to gun violence that affects our city.”

Gun violence hit home to CPD last night as an off duty officer was shot & critically wounded when a gunman fired from a vehicle and hit the officer in the 200 blk of 37th street. He is currently in emergency surgery and we will have more info at a press update at 1030am @ CPD HQ pic.twitter.com/4hH9dRMvzu — Anthony Guglielmi (@AJGuglielmi) June 26, 2019

Some surveillance footage was recovered, though Johnson declined to say what it captured. The superintendent said the shooting “quite possibly” could have been a case of mistaken identity.

He headed to the hospital after the news conference.

Police taped off a stretch of 37th Street between Michigan Avenue and Giles Avenue as officers investigated the shooting. Several police vehicles remained at the scene more than nine hours after the gunfire.

No one is in custody as Area Central detectives investigate.

Kevin Graham, president of the Fraternal Order of Police Lodge 7, the union that represents rank-and-file officers, said the union’s peer support staff was with the officer’s family Wednesday morning. Support services have also been made available to the officer’s colleagues in the Gresham District.

Ida B. Wells Preparatory Elementary Academy sits at 249 E. 37th Street. Chicago Public Schools ended the 2018-2019 academic year on June 18.

Contributing: Sun-Times Wire