Houston doctor's killing may be due to '20-year-old grudge: police

(Reuters) - Houston police issued an arrest warrant on Wednesday for the man suspected of shooting dead a cardiologist who once treated former U.S. President George H.W. Bush, saying that a 20-year-old grudge may have motivated the shooting.

Police identified the suspect as Joseph James Pappas, 65. They said that Pappas' mother died while the cardiologist, Mark Hausknecht, was performing surgery on her 20 years ago.

"It appears that this may be a 20-year-old grudge that this man held, and sadly we have a person (who) lost their life," Houston Police Chief Art Acevedo told reporters.

Police named Pappas as a suspect in the murder after several people, who were not named, identified him after viewing enhanced surveillance video from a home, Acevedo said.

Police visited the suspect's home on Tuesday and Wednesday but did not find him, police said.

"He is considered to be armed and dangerous, and people should not try to deal with him directly," Acevedo said.

Hausknecht was fatally shot on July 20 as he rode his bicycle to work at the city's bustling medical center, when a man also riding a bicycle fired at least two shots at him before pedaling away.

Hausknecht, who had worked in Houston for about three decades, had once treated Bush for an irregular heartbeat.

(Reporting by Makini Brice; Editing by Phil Berlowitz)