British police have made public a stabbing victim’s skull X-ray as they search for two suspects wanted in a horrific bus stop assault last year.

The 15-year-old victim, who was not identified, was stabbed in the forehead last November after he and two other friends tried to stop a robbery at a south London bus stop, the U.K.’s Daily Mail reported. The boy’s friends were also stabbed.

The victim was rushed to the hospital with the kitchen knife still lodged in his head. Doctors said that the teen would have died if anyone tried to remove the knife themselves.

One of the three suspects, who dropped a hat and his cell phone while fleeing, was arrested a short time after the attack. He is to be sentenced next month.