Update 4:20 pm
Police said they searched Chasen's home and office on Tuesday afternoon.
"We don't have anything at this point," said Sgt. Lincoln Hoshino of the Bevery Hills police department. "The investigation is 12 hours old."
Police did not, however, contact the W Hotel, general manager Jim McPartlin told TheWrap.
McPartlin said there was adequate security outside of Drai's, the club on Hollywood Boulevard belonging to the hotel, where around 600 people gathered for the post-premiere party at about 11 pm.
See slideshow: Ronni Chasen's Last Moments at the 'Burlesque' Afterparty
Chasen valeted her car there, according to her close friend Vivian Mayer who saw her at the party.
The valet sits out on the public sidewalk, just next to a busy Metro station, whereas most of the W Hotel is protected by a deep setback from the curb.
Funeral services for friends and family will be held at 11 am on Sunday at Hillside Memorial, 6001 W. Centinela Avenue, Los Angeles 90045.
Chasen is survived by her brother, screenwriter Larry Cohen.
UPDATE 2:20 p.m. PST. (Keep refreshing for updates)
Longtime publicist Ronni Chasen was found shot multiple times early Tuesday in Beverly Hills and later died in the hospital, sending a shockwave through the entertainment community that knew her for decades. Many had seen her at a lavish Hollywood afterparty just minutes before her violent death.
Chasen was shot five times in the chest, then crashed her late-model Mercedes-Benz E350 into a light pole around 12:28 a.m. near Sunset and Whittier, authorities told TheWrap. It wasn't immediately clear whether the car was moving when she was shot, and no one else was in it when police arrived.
The investigation was in preliminary stages, and no suspects or motive had been identified. But police were considering several possibilities, including that she may have encountered a robber on her way home.
Vivian Mayer, one of Chasen's best friends, told TheWrap that she had parked at the new W Hotel in Hollywood, where she was attending an afterparty for the world premiere of "Burlesque" at the Grauman's Chinese Theater a few blocks away. No one saw Chasen leave, or whether she left with anyone, Mayer said.
Chasen lived in Westwood, and was likely driving home when she was shot near the busy intersection about five miles from the party. People who lived nearby told the Los Angeles Times that they heard rapid gunfire and ran to the car, where Chasen, whose window was shattered, was still alive and breathing heavily but not responsive. (Photo below right from myFOXla.com).
Chasen was single, had no children,and had been once married and divorced, in her 20s. She wasn't known to be dating anyone at the time of her death, her friends told TheWrap. She was the sister of Larry Cohen, a successful genre screenwriter and director whose credits include "Phone Booth."
People close to Chasen said police were working on a few theories, primarily that someone might have encountered her outside the W Hotel -- situated in a down-at-the-heels part of Hollywood -- and gotten in her car. They're also considering a road-rage incident, though Chasen's friends consider that antithetical to her personality.
Chasen was likely attending the "Burlesque" screening because Diane Warren, one of her clients, had written a song in the film. Its stars -- Cher, Christina Aguilera and Kristen Bell -- were all in attendance.
The news came as a lightning shock to the entertainment community. Chasen has been a well-known figure in publicity for four decades.
Joe Roth, the producer of "Alice in Wonderland" and a client of Chasen's wrote TheWrap that he was "shocked":
"She was my friend for thirty five years," he wrote. "Ronni was a dogged champion of movies and we all will feel her loss. Its inconceivable actually."
"All of us in personal publicity are devastated by this tragic loss," fellow publicist Kelly Bush said in a statement. "Ronni was a terrific publicist, blazing a trail for women in this business, like few others. I greatly admired and respected her. Our thoughts are with her family, friends and staff."
"Ronni was smart and quirky and talented and the world will be a lesser place without her," publicist Howard Bragman told TheWrap.
She has been a constant figure on the Academy Awards circuit, pushing hard for her clients including "Wall Street: Money Never Sleeps," composer Hans Zimmer and producer Joe Roth's "Alice in Wonderland."
Indeed, it was her work on behalf of Sony's Oscar campaign that brought her to the "Burlesque" premiere on Monday night.
Jeff Sanderson was Chasen’s partner at Chasen & Co., having first worked for her when Chasen ran publicity at MGM in the 1980s.
“It is devastating,” he said. “Ronni was one of my best friends. Worked together for 15 years. She was my mentor and a wonderful partner.”
Chasen (at right with director Danny Boyle) has been a staple in the industry for four decades. Beginning her career in 1972, she went on to work for major studios such as Disney and Fox, as well as films such as "Driving Miss Daisy" and "De-Lovely." She rose through the ranks at Rogers & Cowan before leaving to open her own firm Chasen & Company, which primarily represented composers and other music-related Oscar campaigns for individuals and studios.
Police are asking for the public's help; anyone with information is asked to call 310.288.2656
Josh Dickey, Tim Molloy and Jeff Sneider contributed to this report.