A local police official confirmed that the victim was a physician but offered no further details about him or the shooting suspect, who he said was detained at the scene without incident.
"This is nuts. People are just shooting everyone all the time," said Becky Calerwood, who works two doors down from the office where the slaying took place, as quoted in a Los Angeles Times report on Tuesday.
"I sit right at the front desk. I would have caught the first bullet," she added.
Calderwood further elaborated that the gunman was a 70-year-old patient.
According to the report, several individuals at the shooting site have identified the slain victim as a urologist, but police withheld his identity pending notification of relatives.
According to a Newport Beach police spokeswoman, callers reported hearing six or seven shots t at about 2:45 on Monday.
"We won't know a motive until our detectives have a chance to interview the suspect later" added the police official.
A US medical doctor has been shot and killed by his elderly patient at an examination room affiliated with a nearby California hospital.
The incident occurred in mid afternoon on Monday in an office building reportedly linked to the nearby Hoag Hospital in the affluent town of Newport Beach, police announced.