The two former patients, one speaking on condition of anonymity, also told The Associated Press that Hacking once ran unauthorized group therapy sessions.
Hacking, 28, is in jail and accused of killing his wife and disposing of her body in a garbage bin. Lori Hacking, 27, is believed by authorities to have discovered that her husband had been lying for years about his education and plans to become a doctor.
The couple had packed for a move to a North Carolina medical school where, it turns out, he wasn't enrolled. Hacking's family was astonished to discover he had also been lying about having graduated from college.
The University of Utah said Friday that Hacking ran group "activities," not therapy sessions, although the former patients recalled Hacking relishing a role as therapist - asking about their concerns and taking notes on their behavior.
They said he acted "like a person in authority" and rewarded them with cigarette breaks.
Former patient Nedzad "Ned" Rosic said Hacking was known as a "psych tech" but acted as a therapist while "shaving his head and pretending to be Franz."
Hospital officials confirm Hacking wore a "Franz" name tag but say it wouldn't have been officially issued.
"Apparently there was a period, taking off on a 'Saturday Night Live' skit, when he introduced himself as 'Franz,"' said University of Utah hospital spokeswoman Ann Brillinger. "Hans and Franz" was a skit featuring a pair of narcissistic bodybuilders.
Administrators at the University Neuropsychiatric Institute refused to take calls from the AP on Hacking's conduct on the job he resigned July 23. Brillinger said Friday she was providing answers she obtained from institute staffers she didn't identify.
Hacking was licensed by Utah as a health care assistant, a position equivalent to his job title at the institute, which was psychiatric technician, Brillinger said.
Such employees work under the direction of nurses and deal with patients' basic needs, but aren't allowed to provide counseling, Brillinger said.
Hacking also went by another alias, Jonathan Long, giving it to officials when his family admitted him at the University of Utah Medical Center psychiatric ward. The hospital is not where Hacking worked.
Hacking was admitted the night after the search for his wife began, after police found him running around naked in sandals outside a motel where he had taken a room.
Salt Lake police are searching for Lori Hacking's remains at a municipal landfill. Two of Hacking's brothers who visited him at the psychiatric ward July 24 said he confessed to them to having killed his wife and putting her body in the trash.
Hacking's attorney, Gil Athay, has said he will raise the issue of mental illness and challenge his client's confession to relatives.
Lori Hacking's father, Eraldo Soares, issued a statement Friday expressing outrage with the apparent "cold-blooded" murder of his adopted daughter and assailing her husband's "selfish and shameful" deceptions.
By Paul Foy