LOS ANGELES - Police launched an intensive search Thursday for the killer who gunned down the only son of entertainer Bill Cosby.
The pain of the apparently random tragedy resonated across a nation that has embraced Mr. Cosby as its pre-eminent family man.
Authorities said they believe that Ennis William Cosby - a 27-year-old graduate student who had been the inspiration for some of his father's most touching work - had stopped early Thursday to fix a flat tire on his green Mercedes convertible when he was set upon on a secluded stretch of road above Bel-Air, between Los Angeles' San Fernando Valley and west side.
Mr. Cosby was found at about 1:40 a.m. by a woman who later told authorities that she saw a man leaving the area. Police released only the suspect's race, describing him as a "white male," but said they hope the witness description leads to a composite drawing.
In New York, Mr. Cosby's face appeared crumpled with grief as he arrived at his Manhattan townhome. "He was my hero," Mr. Cosby said.
Shortly before 9 p.m., Mr. Cosby left his home with his wife and one of his daughters. With a police escort, the family left for the airport on their way to California.
The younger Mr. Cosby had been visiting Los Angeles, staying at his family's Pacific Palisades mansion, while on vacation from his studies at Columbia University in New York.
Most of the details of the crime remained a mystery late Thursday, including the identity of the female witness, initially described as a "passer-by" who called police to the scene.
Los Angeles Police Department spokesman Tim McBride said Mr. Cosby knew the woman and was on his way to meet her when his tire went flat.
According to what the woman told investigators, "she came to the scene to help him change the tire, and ultimately became a partial witness," Mr. McBride said.
The woman, who was pursued by the media Thursday, was "freaking out," and fearful the suspect might retaliate against her, Mr. McBride said. "She doesn't want to talk to anybody.
"She's the only one who can identify the suspect," Mr. McBride said. "This is a murder investigation. Disclosing her identity .°.°. could put her at risk."
Nothing the witness told police caused them to alter their initial opinion that "it's a straight crime, and he's a straight victim," Mr. McBride said, adding that Mr. Cosby might have been robbed. "Somebody just saw this nice car and said, `There's some money here, a nice car, maybe I can get some of that.'°"
The elder Mr. Cosby received the news Thursday morning as he was preparing to rehearse for the regular Thursday-evening taping of his new program, Cosby. Mr. McBride said he delivered the news and then talked to the star about the pain of losing a child.
Somber-faced crew members left the studio after the evening's taping of Cosby was canceled. "We've all known Bill Cosby for a long time," said one worker. "This is a terrible tragedy."
Outside Mr. Cosby's $3 million estate in Pacific Palisades, the entertainer's spokesman said Ennis Cosby had been happy and well-adjusted. The family agreed with police suspicions that the crime was random.
While the real-life Ennis kept a low-profile, his alter ego became a staple of America's television diet - the model for the son "Theo" on the blockbuster The Cosby Show. The real and fictional characters shared many struggles - with dyslexia, with ubiquitous sisters, with school work and with a sometimes bumpy adolescence.
Mr. Cosby's private pride in his son became public when the last episode of The Cosby Show aired in the spring of 1992. The program featured Theo's triumphant college graduation, a feat that shortly thereafter would be completed by Ennis, who received his bachelor's degree in psychology from Morehouse College in Atlanta.
Bill Cosby once said he was doubly proud of his son because of the obstacles he had overcome. The boy had once told his father he felt too much pressure to succeed and wanted to be "just regular people," not putting so much energy into his studies. But things began to turn around when educators at Morehouse diagnosed and began to treat Ennis' dyslexia.
On the way to his degree, the younger Mr. Cosby worked at an Atlanta homeless shelter, studying and counseling cocaine addicts who lived there.
"He was not your typical Hollywood kid, if there is such a thing, not the kind that usually ends up in the news," said professor Harold Braithwaite, Ennis' college adviser. "He was a compassionate person and sensitive to other people. That is my strongest, most potent remembrance of him."
He was also intent, Mr. Braithwaite said, on "being accepted as Ennis, not as the son of Bill Cosby."