A man accused of killing one of former President George H.W. Bush's doctors fatally shot himself during a confrontation with authorities in Houston on Friday morning, the city's police chief said.

Joseph James Pappas, 62, was accused of shooting Dr. Mark Hausknecht on July 20, while the cardiologist rode his bike to work at Houston Methodist Hospital. Authorities have said Pappas might have been seeking revenge for his mother, who died on the doctor's operating table more than 20 years ago, in April 1997.

"It's a sad day all the way around. This doesn't bring anybody back. It does bring closure to this community," Houston Police Chief Art Acevedo said of Pappas' death.

Authorities on Wednesday had announced Pappas as a suspect in the death, saying he should be considered armed, dangerous and possibly suicidal.

Police found him Friday after a worker for a local nonprofit reported seeing him around 9:21 a.m. near a community center by a bayou. The worker found a wallet with an ID that belonged to Pappas.

Pappas fled on foot to a nearby neighborhood in southwest Houston, where he was confronted by a police officer. Pappas refused to raise both his hands, keeping his right hand by his hip, Acevedo said. Pappas was wearing a bullet-proof vest and a backpack.

"The suspect said something about suicide and the officer said, 'Let me see some hands,'" Acevedo said.

When a second officer arrived, Pappas raised a revolver he had been hiding in his right hand and fatally shot himself in the head in front of a home, police said. His body was still at the scene Friday afternoon.

Pappas had worked in law enforcement for more than 30 years and was also a licensed real estate broker, state records show. Friday's confrontation occurred about 3 1/2 miles (5 1/2 kilometers) from his Houston home.

Hausknecht was shot in broad daylight at the Texas Medical Center, a 1,345-acre (545-hectare) complex of hospitals and medical institutions that in the morning is busy with traffic, medical professionals heading to work, people going to medical appointments and construction workers.

Autopsy results show he was shot three times, including in the head and torso. Police have said Pappas was a marksman and the shots that Pappas was accused of firing as he also rode on a bike "took some skill."

When police searched Pappas' home on Tuesday, officers found an extensive intelligence file he had put together on Hausknecht, which included detailed information about the doctor's home and his work.

Inside this file was also a list with a dozen names of other doctors and employees at the Texas Medical Center, said Acevedo, adding that authorities didn't consider this a "hit list." Those names were turned over to the medical center.

According to a charging document released on Friday, police also found in Pappas' home three boxes of .22-caliber ammunition, the same type that was recovered from the scene of Hausknecht's shooting. Police also found what was described as Pappas' "last will and testament."

Pappas had worked from 1983 through 1995 as a peace officer with two Houston-area constable offices. He also worked from 1995 through 2013 as a reserve officer for these same constable offices, according to records from the Texas Commission on Law Enforcement.

Police said they checked and didn't find evidence that Pappas might have been staying in vacant homes he would have had access to as a real estate broker. They suspect he might have been sleeping outdoors while he had been on the run.

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 (3.2 kilometers) from his office.

In 2000, Hausknecht treated Bush for an irregular heartbeat after the ex-president complained about lightheadedness.

No disciplinary action had ever been taken against Hausknecht, according to the Texas Medical Board.