The FBI revealed the identity of the alleged assassin on Friday (September 12) as 22-year-old Tyler Robinson.
The suspect is a Utah resident and was aware that the MAGA activist was coming to his state long before the shooting unfolded.
The dad-of-two was swiftly rushed to a nearby hospital, where attempts to save his life were unsuccessful.
Speaking in a YouTube clip, neuropsychologist Derek Van Schaik analyzed the footage and revealed whether Kirk would have been aware of what was happening, or even felt any pain.
The expert said: “When someone suffers a catastrophic wound to the neck that destroys a carotid artery and jugular vein, the mind only has a fleeting window to possibly register what happened.”
He added: “However, in Charlie’s case, and after analyzing the footage with a digital timer, he was conscious for no more than four-tenths of a second after impact.
“Far too fast for his brain to even register what had happened to him.”
Van Schaik noted that his death was ‘essentially instant.’
“No panic, no dread, no realization that he was about to die,” he said.
“Only an abrupt blackout. It was neurologically impossible for him to psychologically realize anything was wrong at all.
“He absolutely did not know he was shot.”
The neuropsychologist revealed that pain in the neck can register in just ‘100 milliseconds,’ but that Kirk was not conscious for enough time following the bullet for his brain to turn that raw signal into a perception of pain.
The alleged killer is scheduled to make his first court appearance this afternoon (September 16) in Utah, where prosecutors are expected to formally charge him with murder.