CHICAGO (CBS) — Police said an off-duty officer is showing signs of improvement after he was critically wounded when he was shot in the head while driving in the Bronzeville neighborhood overnight.

Police Supt. Eddie Johnson said the officer was driving near 37th and Prairie around 1:30 a.m., when he and his female passenger noticed a black Toyota following them. They called 911, and seconds later a gunman in the vehicle following them opened fire, shooting the officer in the head.

The 25-year-old officer was shot in the head and crashed into a stop sign, the fence of a nearby elementary school and a tree before his personal vehicle came to a stop, Johnson said.

“My heart goes out to this young man’s family and his friends as well,” Johnson said Wednesday morning at Chicago Police Headquarters. “These senseless shootings just have to stop. Chicago police officers are part of the fabric of this city, and this goes beyond the time we’re wearing uniforms and badges. The smae gun violence affects our communities, affects us all.”

Johnson said officers conducting a traffic stop nearby heard the gunfire and responded to the scene. He also said private video cameras nearby captured part of the shooting.

The superintendent said detectives are looking into whether or not the officer was targeted. Johnson said it’s possible the shooting was a case of mistaken identity.

The wounded officer was taken to the University of Chicago Medical Center where he underwent emergency surgery. Johnson said the officer was in critical condition but showing signs of improvement. He was visited by Johnson and Mayor Lori Lightfoot.

“It’s encouraging right now because he is responding to stimuli. He’s responding to verbal communication, and he actually gave a thumbs up,” Johnson said.

In a statement Wednesday afternoon, Lightfoot said, “No parent should ever have to receive the news that their child has been shot and joined the growing ranks of gun violence victims. Again today our hearts are heavy with the news that an off-duty Chicago police officer was shot and critically injured.

“As his parents, friends and co-workers hold vigil at his bedside, we must find the will as a community to say enough is enough. We must come together to stem the gun violence that too many residents and neighborhoods know all too well. I ask every Chicagoan to keep all of our victims of gun violence in your prayers and today say a special prayer for the officer, his family, and the Sixth District,” she added.

Chicago Fraternal Order of Police President Kevin Graham said fellow officers from the 6th District visited the wounded officer at the hospital and prayed together for a full recovery.

“I would ask everyone to please keep him and his family and the 6th District and the officers of the Chicago Police Department in their thoughts and prayers today because I think that is what’s going to really get him to pull through,” Graham said.

Police have not released the officer’s name, but the wounded 25-year-old officer has close personal ties to Johnson. His father, a retired officer, worked alongside Johnson for several years at the 6th District before Johnson became superintendent. The officer and Johnson’s son now work together at the same police district. He has been on the force for two years.

“These are the tough days. I worked with his dad for many years as a patrolman in the 6th. I was a patrolman in the 6th for 10 years and then went back as a commander, so I have a really good relationship with his father,” he said. “And then his son comes on the job along with my son, and now they know each other really well and are working together. So it’s difficult.”

No one was in custody Wednesday morning. Johnson asked anyone who might know anything about the shooting to call Area Central detectives at 312-747-8380, or to submit an anonymous tip online at CPDTip.com.