Hollywood publicist gunned down off Sunset Boulevard

She was beloved by all of Hollywood and had just taken her leave from the kind of evening she loved: schmoozing the stars and the media poolside on the roof of a swanky Beverly Hills hotel. Then, on the way home in her new Mercedes-Benz, veteran film publicist Ronni Chasen was shot dead.

It is a murder as shocking as it is inexplicable. No one, least of all police investigators, have so far been able to offer any concrete clues as to why anyone would want the single, 64-year-old fixture of the studio scene dead. It has dazed many of the top shakers in the industry, as well as the residents of Beverly Hills, one of the safest neighbourhoods of Los Angeles; one which didn't see a single killing last year.

The geography of the assassination was clear enough. Seemingly after leaving a party following the premiere of the film Burlesque starring Cher – who was present – Ms Chasen got in her car to drive to her home in the Westwood area. Residents on a tree-lined avenue along the route, just south of Sunset Boulevard, heard shots fired at about 12.28am on Tuesday and saw her car skidding into a lamppost, with Ms Chasen slumped at the wheel and struggling to breathe. She was rushed to a nearby hospital, but was pronounced dead as a result of gunshot wounds to the chest.

"We are heartbroken, shocked and completely devastated," said Amy Pascal, co-chair of Sony Pictures, the studio behind Burlesque. She said that at the premiere Chasen had been "full of her trademark energy and love of life".

As news of the murder spread, several studios closed for the day.

Police in Beverly Hills said last night that as part of a "thorough investigation" they had begun collecting footage from surveillance cameras along the route Ms Chasen took before she was shot. Private homes and businesses have cameras mounted along sections of Sunset Boulevard, although because it was at night the quality of footage is likely to vary significantly. It may give an indication, however, whether a car might have been in pursuit of the Mercedes.

With a career spanning four decades, Ms Chasen was best known for running campaigns in the run-up to the Academy Awards. She had an Oscar in her sights for the musical soundtrack of Burlesque. Other films she had promoted over the years include Driving Miss Daisy, On Golden Pond and last year's Best Picture winner, The Hurt Locker.

Recently, Ms Chasen was taken on to help generate a supporting role Oscar for Michael Douglas in the remake of the film Wall Street.

Actor Morgan Freeman spoke of his "extreme pleasure" in working with Ms Chasen on Driving Miss Daisy.

"We've been friends ever since," he said, on hearing of her death. "She is someone I greatly admired and she will be remembered."

Police said they had no witnesses to the shooting itself. As they launched their investigation they removed computers and hard drives both from Ms Chasen's apartment and from the offices of her firm, Chasen and Co.

"To think of not being able to get her on the other line of the phone is unimaginable," said veteran producer Richard Zanuck. "She was the best publicist in the business."