Oakland police released surveillance-camera photos Wednesday of a man and a woman suspected of robbing $17 from a visitor from Virginia before shooting him to death.

Police say the grainy photos, taken from a video camera outside a nearby office building, show a man and woman walking together on the 1900 block of Webster Street in downtown Oakland moments before computer engineer Jinghong Kang, 45, of Fairfax, Va., was shot and killed at about 11:30 p.m. Sunday.

The photos don't show the robbery or killing, but police said the two people pictured match descriptions of the assailants provided by a companion of Kang's.

Both suspects are black. Investigators described the man as 18 to 25 years old, 5-foot-7 to 5-foot-10 and 160 to 170 pounds. He wore a black hooded sweatshirt, dark pants and dark shoes.

Investigators said the woman was 18 to 25 years old, 5-foot-3 to 5-foot-6 and 140 to 150 pounds. She wore a multicolored jacket, gray baggy sweatpants and white tennis shoes.

Oakland homicide Sgt. Mike Gantt said the two are seen "minutes before the murder. We believe these individuals may be involved in this murder."

Kang, a father of three sons, had gotten his teeth cleaned earlier in the evening and had returned to his rental car with a dental hygienist when he was shot, police said. His dental appointment was in preparation for a job interview that had been scheduled for Monday at Google Inc. in Mountain View, police said.

Investigators said Kang and the hygienist knew each other because they had been members of the same church. She was helping Kang enter directions back to his hotel into the car's GPS system when the two assailants struck.

Kang's companion initially told police that two men were responsible, but that was because both were wearing hoods when they accosted the pair, Gantt said. The video shows the woman with a ponytail before she put her hood on, police said.

Gantt said the man in the video is believed to have pulled the trigger after demanding money. Kang handed over the $17 he had on him, but the man shot him anyway, police said. The hygienist was not hurt.

"It's senseless," Gantt said. "I'm tired of investigating homicides like this when people are killing people like a life means nothing. Seventeen dollars - is your life worth $17? I don't think so. I think it's worth more than $17. You can't put a price on a life."

Gantt added, "People have the right to be out whatever time of day or night they want to be in. This is a free country, and (Kang and his companion) were just out minding their own business."