Police issue warrant in killing of Bush snr's doctor, say suspect held 20-year grudge

Former US President George H.W. Bush with his cardiologist, Mark Hausknecht in 2000. Photo / AP file

Joseph James Pappas. Photo / AP

Houston Police issued an arrest warrant for a man suspected to be responsible for the fatal shooting of former US President George H.W. Bush's personal doctor.

The shooting occurred on the morning of July 20, according to police, while Mark Hausknecht biked to work.

Houston Police said they searched the home of Joseph James Pappas, the suspected gunman and are actively looking for him.

Police said the 62-year-old white male has for more than 20 years held a grudge against Hausknecht after his mother died during an operation.

"This man is dangerous, this man is capable, this man has some skills," Houston Police Chief Art Acevedo said at news conference, according to the Houston Chronicle, noting he likely had multiple firearms and had not been seen for nearly two days.

The fatal shooting occurred after the suspected gunman followed Hausknecht by bike to work at Houston Methodist Hospital. The suspected gunman shot the cardiologist twice in his torso less than 1.5km from the hospital.

"There was a lot of planning that went into this," Acevedo said. "There was a lot of planning and sadly some skill."

Hausknecht treated Bush snr for heart problems in 2000.

"Mark was a fantastic cardiologist and a good man," Bush said in a July statement. "I will always be grateful for his exceptional, compassionate care. His family is in our prayers."