Crime Library: Criminal Minds and Methods

Investigation into the Murder of Dr. David Cornbleet

Unknown Suspect

A still from the surveillance video.
A still from the surveillance video.

Surveillance videos show an unknown male walking into the office building on Michigan Avenue that day at 4:45 p.m. He was a Caucasian male, approximately six feet tall. He was wearing a red baseball cap, with an unidentifiable symbol on the front, a gray or cream-colored hooded jacket and either blue or black pants. He also had a dark messenger bag slung over his back. He opened the front door with a white glove, in an apparent attempt to mask his fingerprints.

The man was obviously familiar with the building, carefully hiding his face from the surveillance cameras. As he neared the elevator he made a cocky, figure skater-style move, twirling on one heel in a circle. He then stepped inside the elevator and ascended to the twelfth floor. His destination was the office of Dr. David Cornbleet.

Once there, the man confronted Dr. Cornbleet, pulled out a knife and attacked. David desperately attempted to defend himself, suffering lacerations to his hands as he attempted to fend off the attacks. At one point, he managed to strike a blow to his attackers face, causing the man's nose to bleed.

David put up an unbelievable fight for a man his age, but sadly he was no match for the younger man, who continued to stab him unmercifully. As the fight left his body, David slumped to the floor, and his attacker duct taped his mouth, hands and feet. It is unclear whether David remained alive at this point.

What the killer did next is not entirely clear. Evidence from the scene suggests he used an exam room sink to wash the blood from his face and hands. He then exited the office, some 45 minutes after the cameras had caught his arrival. On his way down back to the lobby, the elevator stopped, and a woman stepped inside. The killer avoided eye contact, covering his face the entire time. When the elevator reached the lobby, the killer proceeded out the front entrance, and the woman immediately walked to the reception desk. She notified the receptionist that the man in the elevator had been "covered in blood" and "breathing hard." She would later describe him to investigators as in his late teens to mid 20s, with short blonde or light brown hair, possibly curled or wavy.

Another still from the surveillance video.
Another still from the surveillance video.

From the surveillance videos showing his departure it is clear the killer had taken off his ball cap and replaced it with a black skullcap. He had also removed his jacket, which he used to cover his face. Some early reports suggested he might have taken medical records, because of an unknown object protruding from the messenger bag. However, Jonathan said that was not the case.

"In addition to the records at my dad's office, he also kept index cards at home, which listed all his patients," he said.

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