"They attempted to talk to the suspect. When they did, the suspect produced a handgun and there was a self-inflicted gunshot wound," said LAPD Capt. Kevin McClure.
The man was declared dead at the scene. He has been identified as Harold Smith, a convicted felon. Neighbors described him as unusual, perhaps mentally unstable, and also said he would brag about playing a role in the Ronni Chasen murder.
"He said he offed her, and he was going to get paid some money," said resident Terri Lynn Gilpin.
Beverly Hills Police did not comment on the suicide or the reason they wanted to talk to the man.
"The way he kept talking about if he ever got caught or if the police ever caught him, he was never going back to prison," Gilpin said. "He said he'd die first."
"He told my husband all the time, 'I have a gun, I have a gun. If anybody pisses me off me, someone's going to die,'" said Gilpin.
Sammy Zamorano says he saw the man a minute before police arrived. They passed each other on the sidewalk.
"I looked at him straight in the eye," said Zamorano, who owns a music studio nearby. "And I walked in my studio and five minutes after I hear 'Boom.' I walk out and in front of the door, I see him through the door, and a cop is trying to shut the door on me, says 'Get out of here!'"
Investigators will be taking a good look at the weapon the man used to kill himself. Forensics experts will likely be checking if the weapon matches the one used in the Chasen murder.
Authorities will also be taking a look into whether the man was mentally ill, heard about the Chasen murder and decided to take credit for it.
"To me, it's no conspiracy. This guy wasn't intelligent enough," said Zamorano.
Court documents were released Thursday showing Chasen had an estimated worth of more than $6 million. She reportedly left a lot of money to various charities, but apparently intentionally snubbed one of her nieces, leaving her $10.
Chasen, 64, was killed on Nov. 16 as she was driving in her Mercedes-Benz through Beverly Hills after attending a Hollywood premiere party for "Burlesque." She had been shot several times in the chest.
A leaked coroner's report raised more questions, including whether the gunman was a hired killer.
ABC News has seen a copy of the initial coroner's report, which is now under a security hold. The report says one bullet was recovered from her back while at the hospital and is possibly a 9mm hollow-point.
Chasen received three apparent wounds to the right-side breast/chest area and two apparent gunshot wounds to the right shoulder.
Detectives suspect the gunfire came from an SUV or a truck pulling alongside her car, and say it appears the shooter was an expert marksman.
"Normally they turn that gun sideways ,and this is something that's done with some skill," said former L.A. County Sheriff's Dept. homicide detective Gil Carrillo. "I'll be honest with you: I've carried a gun for 38 years and had to qualify quarterly. I don't know that I could shoot and hit that mass like that."
Carrillo was a homicide detective for more than 20 years in Los Angeles.
"My gut tells me that somebody contracted someone else to kill the victim," Carrillo said.
The location has been called the "Bermuda Triangle of Beverly Hills" because it's near the area where Howard Hughes survived a plane crash in 1946 and where Bugsy Siegel was gunned down on the street.