Beverly Hills mayor Jimmy Delshad said Thursday night detectives have determined "Ronni Chasen was targeted."
Delshad told NBCLA reporter Robert Kovacik that investigators believe the publicist was murdered in a car-to-car shooting.
"She was shot through the passenger window as she made a left onto Whittier from Sunset (Boulevard)," the mayor said.
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Delshad said, "due to the high angle of shots fired it is believed" investigators believe the suspect's "car was a SUV."
Delshad said police believe Chasen was shot at the intersection of Sunset and Whittier. Glass was found near the intersection. As for those mysterious casings missing from the crime scene Delshad said there was speculation the shells were inside the vehicle used during the slaying.
Meanwhile the Associated Press reported Thursday night the slaying of one of their own has united the competitive community of behind-the-scenes Hollywood publicists, prompting them to contribute big bucks for reward money to find the killer.
Chasen, well-known for working tirelessly to promote her celebrity clients, was shot to death in her car as she drove home from a party after attending Tuesday's premiere of the new Cher and Christina Aguilera movie, "Burlesque.''
Tributes flowed quickly from her stunned community and, absent any hard leads in the homicide investigation, so did money.
The Palm Springs International Film Festival, which Chasen worked with for many years, on Wednesday offered a $100,000 reward for information leading to the conviction of her killer. Fellow publicist Michael Levine a day earlier started a fund and hoped to raise an additional $25,000 by the end of the week.
"A very good lady, a good friend and a genius at her craft. Her death is very, very sad and mystifying,'' festival chairman Harold Matzner said in a statement.
Though by no means a household name, Chasen was a celebrity in her own right to those who work to promote Hollywood movies and their stars. Friends remembered her as an old-school publicist, one with a distinctive, brassy voice who could be relentlessly pushy and loud.
But at the same time, they said, she was never rude and seemed to have no enemies.
Police searched Chasen's Los Angeles condo and her West Hollywood office but had little immediate insight into who might have wanted to harm her.
Chasen, 64, was shot multiple times in the chest as she drove through Beverly Hills around 12:30 a.m. Tuesday.
Neighbors reported hearing gunfire and found Chasen's car crashed into a light pole on Whittier Drive, a street of multimillion-dollar homes just south of Sunset Boulevard, and a well-used shortcut to get to her home on the Westside of Los Angeles.
On Wednesday, at least one bus company that takes tourists past famous Hollywood sights was stopping to let customers gawk at the scene of the killing.
Her friends and colleagues wondered how the life of a woman who had spent her career rushing from red carpet to red carpet to charm the connected for her star clientele could have ended in such a violent way.
``I mean, a publicist doesn't make that type of enemies,'' said Chasen's longtime friend, Oscar-nominated singer-songwriter Carol Connors, who co-wrote the theme to the film ``Rocky.''
Even in the sometimes cutthroat world of fighting for celebrity clients, Chasen stood out for her kindness and willingness to share credit, New York-based publicist Kathie Berlin said.
Berlin recalled a time years ago when the two were promoting the film ``Thelma & Louise'' and Chasen made sure Berlin shared credit for landing the film's stars, Geena Davis and Susan Sarandon, on the cover of Time magazine.
"We both worked on it, but truth is she made the call that got the cover,'' Berlin said.
Unless Chasen was leading some sort of secret life no one knew about, several people said, she'd be the last person they would suspect would be targeted.
She had little time for a secret life, they said, balancing her work with dining out at the trendiest restaurants just about every night and day of the week. She was always in the company of friends and clients _ who were often both.
"She worked all the time,'' publicist James Bates said. ``Her life was going from red carpet to red carpet.''
Rogers reported from Los Angeles and Watkins from Beverly Hills. Associated Press writers Linda Deutsch and Raquel Maria Dillon contributed to this story.