ON MARCH 13, THE DAY AFTER L.A. police arrested Mikail Markhasev for the murder of Ennis Cosby, Bill Cosby went to work. Arriving at a Queens, N.Y., studio to wrap the season's final episode of the CBS sitcom Cosby, the comedian was greeted by staffers wearing black T-shirts—gifts from Cosby—emblazoned with his son's favorite greeting, "Hello, Friend." But on this day, Cosby, despite the turn of events, chose not to mention Ennis to the studio audience, as he had soon after his son's death. "It was like nothing ever happened," says Godfrey, the comic who warmed up the audience. "The show just went on."

In fact it is now up to the criminal justice system to speak about what happened that fateful night in L.A. Ennis, 27, a doctoral student at Columbia University's Teachers College, was on a desolate stretch of road off the 405 freeway on Jan. 16 when, after stopping to fix a flat on a Mercedes-Benz 600L, he was shot in the head. Markhasev, 18, a Ukrainian immigrant, was found after police pursued a tip received in January by the National Enquirer, which offered a $100,000 reward. The likely motive: robbery. Speaking for Bill and Camille Cosby, who were in South Africa last week as guests of President Nelson Mandela, Essence publisher Ed Lewis told PEOPLE, "They are relieved and thankful to the police for their persistence."

The young man police charged with killing Ennis had a promising start after moving to L.A. in 1989. Two years after his arrival he was enrolled in the gifted children's program at Burroughs Middle School. He lived with his mother, Victoria, a dressmaker, and her second husband, Dimitri Goren. Markhasev was "a very honest boy, always very good," according to his aunt Helena Markhesova, who still lives in her nephew's industrial hometown of Lvov, Ukraine. "You know how children are—if you give them candy they keep it. If I gave him candy, he'd say, 'Auntie, have some.' "

By 15, Markhasev had started socializing with the Latino petty street gang Varrio Los Alamitos. After transferring to Reseda High School in 1995, he continued to unravel. He served six months at Orange County's Los Piños juvenile detention center for the October 1995 stabbing of a black man at a gas station. "He didn't like black people," says pal Angel "Sad Boy" Usi, 16. "If he saw someone black, he'd say, 'He's a punk, and we don't need those people here.' " Last month he was cited for marijuana possession and pleaded guilty in court just hours before police picked him up for Cosby's murder. Markhasev's girlfriend Maggie Ruiz, 16, knew him differently. "He never got mad," she says. "He was always friendly to people."

Markhasev's relatives are also standing by him. "I do not believe murder was committed by the hand of our boy," says his aunt Helena. Still, police have recovered the murder weapon, and what they believe is a hat the murderer wore, in an area only five miles from the crime scene. Though Markhasev is remaining silent (he is scheduled to be arraigned on March 28), authorities feel they have a strong case to present.

The Cosby family, in the meantime, has erected a Thank You, Friend sign at the murder site to thank the anonymous tipster. "It's hard to say they're really happy and overjoyed that they found a suspect," says a Cosby friend, "but it was the next step, something to grab on to." Indeed, Lewis says that time may ease the Cosbys' loss, but nothing can make it go away. "When you lose someone you bring into the world," he says, "there's never closure."

A number of celebrities who have lost children agree: There really is no end to the grieving. Herewith, stars who have shared Bill Cosby's heartbreak talk about enduring life's greatest loss.

This week's cover

On Newsstands Now!

Saved by the Bell Reunion

The hookups, the meltdowns, the memoires

The case reveals what was really going on what they think of each other now!

Get 4 FREE PREVIEW Issues! Click here now