A mentally ill convenience store operator took a revolver with him to look for the doctor he believed implanted a tracking device in his body during an appendectomy in 2001. Told the doctor wasn't at the hospital, he went to a nearby parking lot and opened fire on three hospital workers he apparently didn't know, killing one of them.
Gunman Abdo Ibssa entered a medical tower near Parkwest Medical Center before Monday's attack and asked for the doctor who performed the appendectomy, Knoxville Police Chief Sterling Owen IV said. Unable to find the doctor, Ibssa went to another area where patients are discharged and opened fire on the women as they walked out of the building.
Ibssa, who police believe had been skipping doses of medication for psychotic behavior, killed himself to end the shooting, which occurred a day before his 39th birthday.
"There was less than 5 seconds from the time of the first shot until the last shot," Owen said at a news conference Tuesday.
Investigators found a note at Ibssa's Knoxville apartment in which the gunman said the doctor had implanted a chip that was being used to track his movements, Owen said.
Ibssa had a successful appendectomy at Premier Surgical Associates in November 2001 and suffered no complications, according to a statement from CEO Kevin Burris. Police and Burris declined to identify the doctor who treated him, but Burris confirmed that Ibssa was at the medical office Monday looking for the surgeon.
Haloperidol, an antipsychotic medication used to treat schizophrenia and Tourette syndrome, was also found at Ibssa's apartment, but investigators believe he hadn't been using it, Owen said.
Owen said relatives of the naturalized citizen from Ethiopia had him committed for mental treatment in February.
Also found during the search were a second handgun, a bag of marijuana and a copy of the book "The Official CIA Manual of Trickery and Deception" — a reproduction of a Cold War-era CIA handbook on the use of illusion and deception for acts of espionage.
The gun used in the shooting had been reported stolen in March, while other one had an altered serial number but wasn't reported stolen. Police were not sure how Ibssa obtained either gun and said he did not have a handgun permit.
Police said Ibssa operated a convenience store near downtown Knoxville, which was closed Tuesday.
On Monday, a cab driver picked Ibssa up outside his apartment building, and the gunman told him to take him to the western side of Knoxville, eventually specifying the medical center.
Cab driver Freddys Sakhleh said Ibssa said seemed angry and depressed and said little about himself.
Ibssa directed the cab driver to the medical center tower and told to wait for him to come back. Inside, the gunman was told the doctor he sought wasn't there.
When Ibssa returned, Sakhleh said, he told the driver to take him to the hospital entrance where some patients are discharged.
Owen, the police chief, said Ibssa fired four shots at people exiting the building, hitting the three hospital workers. The gunman killed himself with a fifth shot. Police said it doesn't appear he knew the women.
"I called 911, and I said, 'Please send some people here, this man is shooting like crazy,'" Sakhleh said.
The two women who survived the shooting were taken to the trauma center at the University of Tennessee Medical Center. Owen said Tuesday afternoon the women — Ariane Reagan Guerin, 26, and Nancy Chancellor — were in stable condition.
The woman killed was Rachel Wattenbarger, 40. Her father, Ray Wattenbarger, said she had worked at the hospital for about five or six years, helping discharge the elderly.
In January, Ibssa was sued by a man who claimed a 2009 driving incident outside a store escalated into an attack.
The lawsuit by Jalal Boudarga said that Ibssa first used his car to block Bourdaga's vehicle, began yelling at him and then threw him to the ground, breaking his leg. The two didn't know each other before the attack, according to Boudarga's attorney, Jerry Martin.