Updated

A few days ago Beverly Hills authorities reportedly found that the suicide gun used by Harold Martin Smith, 43, the “person of interest” in the Ronni Chasen murder investigation, did not match the gun used in the slaying of the prominent Hollywood publicist.

However, on Wednesday the Beverly Hills Police Department announced that laboratory results confirmed Smith’s suicide gun was indeed used to murder 64-year-old Chasen.

After receiving a tip from an “America’s Most Wanted” viewer that Smith, who was known for wayward behavior and previously served time for felony burglary, was bragging about killing Chasen, police approached him in the lobby of his Hollywood apartment complex. Smith drew a gun and fatally shot himself in the head before police had a chance to question him on his involvement.

Chasen was fatally shot in the early hours of November 16 in a wealthy Beverly Hills neighborhood. No bullet casings were retrieved at the scene and no immediate leads were identified. A nearby Beverly Hills resident  told Pop Tarts that the gun shots were perfectly timed, adding to the previous theory that the killer had very clear, well-executed intentions.

However, Beverly Hills authorities said during Wednesday’s press conference that despite the great deal of public speculation, Chasen’s death was not a result of a professional hit job and that the shooting was a random act of violence.

"We believe most likely it was a robbery gone bad," Beverly Hills Detective Sgt. Mike Publicker. “We believe it was a random act."

After his suicide, Smith’s neighbors told the press that he had said he was going to soon come into $10,000, fueling speculation that he was involved in a paid hit. However, the Beverly Hills Police Department dismissed the theory.

“Reports of Smith proclaiming to get a payout are inaccurate,” Publicker said, adding that no connection between Smith and Chasen seemed to exist prior to the slaying.

Pop Tarts asked Beverly Hills Police Chief David Snowden why the suspect did not take Chasen’s purse, phone or jewelry after the alleged robbery.

“I don’t know, I’ll leave that to the detectives,” he said.

Publicker said Smith may have shot Chasen several times through her car window, but was unable to rob her as she reacted quickly by speeding off.

Prior to Wednesday’s press conference, neighbors of Smith neighbors questioned by FoxNews.com doubted he was involved in the murder at all, and said he was mentally ill. Some legal experts are not convinced that it was a random robbery attempt.

“It just doesn’t seem believable. Chasen had three perfect shots to the chest, which sounds like the work of a professional,” former California prosecutor Robin Sax, who has been closely examining the case, told us. “The notion of Smith coming into $10,000 didn’t just come from nowhere, and the fact that the bullet cases weren’t found indicates that this person knew what they were doing and it was hardly random.”

Santa Monica-based criminal defense attorney Steve Cron doesn’t feel that that the Chasen murder mystery is close to being solved.

“I don’t understand how the BHPD can state that the guns weren’t a match, then suddenly turn around and say the exact opposite. It all seems extremely unprofessional,” Cron said. “Next week they might have another version, it all makes no sense. Given the track record of those on the case, everything they say going forward has to be looked at with a great deal of skepticism."

When asked if Chasen was followed from the "Burlesque" premiere she had just attended, and why she was targeted, Snowden said, “Perhaps he (the killer) just saw her nice car [a Mercedes Benz E-350 sedan] and followed her from there, we don’t know. I’ll leave it to the detectives.”

However, a source closely connected to the hotel where Chasen was last seen said that video surveillance obtained did not show anything suspicious or indicate that Chasen was being pursued.

Authorities also announced at the conference that evidence suggests Smith opened fire while on foot or from his bicycle, which has since been seized by the Los Angeles Police Department.According to neighbors, Smith’s main mode of transport appeared to be a bike which he rode while wearing gray gardening gloves.

Which begs the question: did Smith ride the eight miles from the Harvey Apartments in Hollywood where he resided, to the Sunset Boulevard and Whittier Drive intersection in Beverly Hills where Chasen was shot?

“It is possible, but something just seems wrong. It doesn’t sound conclusive and nobody feels satisfied with this theory,” Sax continued. “There are so many aspects of this that don’t make sense. I am not convinced that it wasn’t a calculated hit.”

To add more confusion into the mix, on Monday the BHPD announced that they were looking for the driver of a black Lincoln Town Car seen on surveillance video from the night of Chasen’s murder. The footage captured by the security camera reportedly shows the car drive by just moments after Chasen’s car crashed into a sidewalk pole.

While Snowden declared that the bike was the murderer’s mode of transport, he declined to comment whether or not it was seen in the surveillance video.

According to Los Angeles criminal defense attorney Angelyn Gates, it is likely police will now perform a gun residue test on Smith’s bike to determine when he used the firearm.

“In theory, there could be, and should be, residue on the bicycle, which would be a huge indicator,” she explained. “Unless he was smart enough to think his bike has residue on it and he took a scrub brush and washed it down, they should be able to find some residue on the bike.”

Gates is also perplexed by the sudden change in police theories. Up until now, it was reported that Chasen was shot from a higher angle and more than likely by someone in a vehicle like an SUV. And immediately after the shots were fired, Beverly Hills residents in the vicinity were on the scene, but no other people or cars were spotted.

“I don't know why in the initial reports they (the authorities) were saying it couldn't be someone from the streets or the sidewalk because now they're saying completely the opposite. [Smith on a bike] doesn't make a lot of sense because nobody from the original reports said anything about a guy on a bike and it's hard to get away on a bike fast,” Gates said.

Then there is the issue of the weapon and ammunition. A three-page preliminary coroner's report obtained by Fox 11 News indicates a "9mm hollow-point" bullet was recovered from Chasen's back at Cedars-Sinai hospital, where she was pronounced dead.

“They were reportedly 9 millimeter bullets used to kill Chasen but there were no casings at the scene, which means that it would need to be a revolver,” Gates said. “I suppose technically it could be possible with semi automatic handguns and those rounds that the casings that were ejected could have vanished or disappeared, but you would expect since the police were out there pretty quickly after it occurred they would have been able to pull out at least one of the cartridges.”

Police declined to comment on the report and have said the information should never have been released. But a source close to the investigation, who spoke under the condition of anonymity, told CBS News this week that the gun Smith used to take his own life was a revolver, but was not a 9mm caliber.

Authorities said Wednesday that the investigation is ongoing, that there are a number of interviews that are yet to be conducted, and that the majority of information from “sources” swirling through the press was “erroneous.”

“We just wanted to announce we had a match, that was it,” a somewhat flustered Snowden said, after being showered with questions he was unable to answer following the press conference.

Given the apparent inconsistencies surrounding the case, Gates believes police may have announced too much too soon.

“It's way too early for anyone to have any sort of a conclusive opinion, but the one thing that I would be concerned about and caution against for the police department or anyone else is to think Smith shot himself, did it alone, it's a done deal, and case is closed,” she added. “That's not the answer to the question. The 'who' is not as important as the ‘why.’?”

- Deidre Behar contributed to this report.