The plan that had been gestating in his mind took real form on 31 July 1966, with the purchase of binoculars and a Bowie knife, as well as some supplies. That evening, he began typing a final letter of explanation, which detailed his irrational thoughts, and failure to find any respite from them. He requested a formal autopsy of his body, to establish whether any physical cause might prove to be the source of his mental anguish.
He outlined his plan to kill his wife that evening, to enable her to avoid any suffering, and would have continued his typing, but he was interrupted by the unexpected arrival of family friends, who stayed for a while, noticing nothing unusual about his behaviour.
After picking up Kathy from work that evening, they returned home, where he phoned his mother and asked if they could come around to visit. For some reason, Kathy chose not to accompany him and he went to his mother’s apartment alone, where he choked her with a length of rubber hose, before stabbing her with a hunting knife. He then sat down and wrote another letter, explaining that he had killed his mother to alleviate her suffering, and stuck the letter on the door of her apartment.
Returning home, he swiftly killed his wife Kathy by stabbing her as she slept, before returning to complete his earlier letter, placing the blame for his actions on his father, before writing notes to both of his brothers and his father. He then set about making preparations for the killing spree that he had planned for later that day.
He packed his old Marine footlocker with all the supplies that he felt might be needed for a lengthy standoff, including food, torches, knives and a selection of rifles and pistols, supplementing these later that morning with additional supplies and more guns, as well as renting a two-wheeled dolly to help him to transport the heavy locker.
Finally, he modified his new shotgun by sawing off part of the barrel and the stock, before loading the dolly and footlocker in his car, donning a pair of blue overalls, and heading for the university campus.  By 11:30 a.m. he had entered the grounds with the use of his security ID, and he unloaded the locker and took an elevator to the top of the tower, where the blue delivery overalls served as a useful camouflage.
Edna Townsley was his first stranger victim: she was supervising the Tower’s observation deck that morning, and Whitman hit her on the back of her head with a rifle butt, before dragging her behind a couch, where she died a few hours later from her wounds. Just before noon, Cheryl Botts and Don Walden entered the reception area from the observation deck and saw Charlie leaning over the couch, holding two guns.  They greeted him but were not immediately alarmed, then boarded the elevator, unaware of how fortunate they were to have escaped the carnage that was to follow.
Subsequent arrivals were not so fortunate: a party of six were greeted by a hail of pellets from the sawn off shotgun, which killed two of them, wounding another two critically, leaving the survivors to run for help.  The alarm spread quickly on lower floors within the tower, and people began barricading themselves into classrooms and offices.
Whitman calmly unpacked his firearms and supplies from the locker, wedged the observation deck door closed with the upended dolly, and took aim at the pedestrians moving along the South Mall far below. His Marine training stood him in good stead, and his first victim there was pregnant student Claire Wilson, whose child was killed instantly by a bullet that pierced her abdomen. Her acquaintance, Thomas Eckman, was also hit in the chest, falling across the injured girl as he went down.  A visiting professor was the next fatality, taking a bullet to the lower back.
Whitman then shifted his focus to the East of the Tower where Thomas Ashton, a Peace Corps trainee, was shot in the chest. Whitman was still moving around the observation deck unchecked, and turned his attention westward, toward Guadalupe Street, a busy street lined with businesses, where three more victims were despatched in quick succession, followed by another three, as the inhabitants unsuccessfully sought cover from the crack marksman.
Austin Police had, by this time, arrived on the scene, and Officer Billy Speed was their first casualty, shot through a six-inch gap between two stone supports of a statue; Whitman’s sharp-shooting skills were easily equal to the police forces now amassed around the tower, who had begun to return fire towards the tower parapet. Private citizens joined in with their own weapons as well, and yet Whitman still managed to kill one more victim, electrician Roy Schmidt, who was more than 500 yards from the Tower at the time.
Through sheer force of numbers, police moved towards the tower, assisting the wounded, making progress upwards towards the observation deck, where they found the door was still wedged shut. Officers Martinez and McCoy finally breached the door, crawling in the direction of Whitman’s gunfire, despite the return fire that was coming from down below, and McCoy managed to shoot Whitman, after which Martinez ran over and also shot Whitman at point blank range. The siege was at an end.
Whitman’s death toll was sixteen; fourteen of whom were shot from the tower, and dozens more were injured during the ninety-minute drama. Investigations soon revealed the bodies of his mother and his wife, as well as the notes that he had left.
His psychiatrist, Dr. Heatly, came under intense scrutiny, when his records revealed the fantasy killing spree that Whitman had outlined during their session, but he was never held accountable for his failure to act.
Interestingly, when Whitman’s body was autopsied, doctors did indeed discover a small tumour in his brain, as he had feared, but experts concluded that this was unlikely to have caused his subsequent actions.  Given that brain science was not as advanced in the mid-sixties, it would be interesting to know if today’s specialists would have drawn the same conclusions.
The observation deck at the Texas tower was reopened soon after the shoot-out, following some repairs, but was forced to close in 1974, following a string of suicides.  It was finally reopened again in 1999, with enhanced security which included a metal detector, security guards on the ground floor and the deck itself, and a steel lattice guard to prevent further suicides.