Former President George Bush, center, waves as he leaves with cardiologist Mark Hausknecht, left, and Bush's family doctor Ben Orman, right, after a news conference at Methodist Hospital Friday, Feb. 25, 2000 in Houston. Bush spent Thursday night in a Florida hospital and was released Friday after being treated for atrial fibrillation. He returned to Houston Friday and was admitted to Methodist Hospital for further tests. (AP Photo/David J. Phillip)
George H.W. Bush's heart doctor shot, killed
01:38 - Source: CNN
Houston CNN  — 

Georgia Hsieh, the wife of renowned cardiologist Mark Hausknecht, says she is struggling to understand why someone would want to kill her husband.

Hausknecht, who treated former President George H.W. Bush, was fatally shot by another cyclist last week as he rode his bike to work, Houston police said.

The cardiologist would spend his free time doing yardwork and cooking and would usually be in bed by 9 p.m., Hsieh says.

Hausknecht was last seen alive Friday dressed in his blue scrubs as he pedaled his yellow bike to Houston Methodist Hospital.

Surveillance images show a suspect following Hausknecht before both pedal out of view, police say. Hsieh says police told her that her husband was riding through a construction area when the gunman rode up in front of him and fired three shots while facing him.

This surveillance image shows a suspect in the shooting of Dr. Mark Hausknecht, police say.

A manhunt is underway for the gunman; it is remains unclear if the shooting was targeted, random or the result of road rage.

As an emergency medicine doctor herself, Hsieh says she has seen firsthand what guns can do. But she never imagined someone she loved would become a victim of gun violence.

Hausknecht spent his career “saving and prolonging the lives of others,” Hsieh said in a statement.

She resisted the suggestion that her husband’s death was senseless, calling it a “trite” way to characterize the scourge of gun violence. What is senseless, she said, “is the misguided notion that any society with more guns is a safer society.”

“So many have asked what can be done to help. While law enforcement has given you their focus on finding the criminal, I am asking you to use your vote and your voice to stem the tide of this growing public health epidemic,” she said in a statement.

She urged people to contact their elected officials and ask them to support “sensible” gun laws.

“We owe it to future generations to leave a safer environment,” she said. “Mark loved this city. To honor him – work hard, be responsible, patient, tolerant and compassionate.”

Images show suspect following doctor

Surveillance video shows Hausknecht riding his bike north on Main Street – followed by a cyclist that investigators believe is the gunman, police say.

Hausknecht, circled in green, was followed by a cyclist, in red, shortly before the shooting, police say.

One image shows the suspect just behind Hausknecht as both head north on Main across West Holcombe Boulevard, police say. In the images posted on Twitter, police highlighted Hausknecht with a green circle, and the suspect with a red circle.

The suspect, circled in red, nears Hasknecht on the road.

The shooting happened moments after that crossing, one block away, police say.

A close-up surveillance image shows the suspect wearing a blue, short-sleeve polo shirt; a khaki or white cap; khaki shorts; and an olive green backpack, police say.

CNN’s Sonia Moghe reported from Houston, while Emanuella Grinberg wrote and reported from Atlanta. CNN’s Nicole Chavez and Jason Hanna contributed to this report.