HOUSTON -- A man suspected of killing one of former President George H.W. Bush's doctors is a former law enforcement officer, CBS affiliate KHOU-TV reports. , 62, also recently tried to sell guns and ammunition online, according to the station.
The items were posted for sale five days after the fatal shooting of. The items for sale included a semi-automatic rifle, a pistol, two bulletproof vests and a bulletproof panel for a Ford Crown Victoria, KHOU-TV reports.
It was unclear if they are connected to the attack. The ads list a phone number that Pappas used on a real estate license and in court papers, according to the station.
Pappas most recently worked as a reserve officer in Harris County, Texas, from 1995 to 2013, according to the station. Before that, he was a deputy constable from 1983 to 1995.
A tip on Tuesday led police to suspect Pappas, Houston police Chief Art Acevedo said at a news conference Wednesday afternoon, though he didn't elaborate as to the nature of the tip. He said the last anyone had heard from Pappas was in a Tuesday morning text message in which Pappas wrote that he was going to kill himself.
Pappas may have been seeking revenge for his mother, who died on Hausknecht's operating table more than 20 years ago, Acevedo said. Pappas should be considered armed, dangerous and possibly suicidal, the chief said.
"There was a lot of planning that went into this. There was a lot of planning and, sadly, some skill," Acevedo said of the July 20 attack.
Hausknecht was gunned down while riding his bike to work at Houston Methodist Hospital, which is part of the busy Texas Medical Center. Authorities say the shooter rode past Hausknecht before turning around and firing.
Acevedo said police searched Pappas' home at 4 a.m. Wednesday and found evidence that ties him to the killing. He declined to elaborate as to the nature of the evidence.
The chief said Pappas is very fit, and that he's likely getting around on his 10-speed bicycle, which he rides "extensively and almost exclusively." Police said the unique Schwinn bike could be the key to catching Pappas, CBS News correspondent Omar Villafranca reports.
Friends and family have described Hausknecht as a humble and generous man who was adored by his patients, volunteered in his community and cared about the environment. Hausknecht was also an avid cyclist and rode his bike to work each morning, as he lived less than 2 miles from his office.
In 2000, Hausknecht treated Mr. Bush for an irregular heartbeat after the ex-president complained about lightheadedness.
Neighbor Jim Herd said he has known Pappas all of his life, having attended the same high school and church as him. Herd described Pappas as a nice, quiet man who kept to himself and had few close friends.
"He was a loner," he said. Pappas' house, in which no one was found Wednesday, is in an older, established neighborhood in southwest Houston.
Most of the homes are single-story ranch homes with neatly manicured lawns. Indeed, Pappas kept a neat yard, Herd said, and he saw Pappas mowing his lawn a week after the doctor was slain.
The house was home to Pappas' parents and their family from the time Pappas was born, Herd said, adding that Pappas inherited the house after his father's death about 10 years ago. Since then, Pappas had lived there alone.
Herd said he and Pappas had few words but would wave at each other in passing — the last time on Saturday, when Pappas waved at him as Herd washed his car in his driveway. Herd said he does not remember ever hearing Pappas speak bitterly about his mother's death or place blame for it.
But "it hit him hard," he said, and Pappas stopped attending church for a long time afterward. After police released photos from surveillance video of the suspect in Hausknecht's slaying, Herd said he thought it resembled Pappas but brushed the notion aside.
"Never in a million years would I have thought it was him," he said.