Ronni Chasen -- Fatal Shots Fired ON Sunset

12/8/2010 9:01 PM PST

Ronni Chasen -- Fatal Shots Fired ON Sunset

Law enforcement sources tell TMZ Beverly Hills detectives believe Ronni Chasen was fatally shot on Sunset Boulevard, but managed to turn left and drive hundreds of yards -- and witnesses may have seen enough to place Harold Smith at the scene.

Our sources say the BHPD is "confident" Smith was the shooter.

Law enforcement sources say there is no surveillance video capturing the shooting. Nevertheless, the BHPD believes Smith was on a bicycle when he attempted to rob Chasen. Although no one will confirm that witnesses saw part or all of the incident ... it would seem that's the only way police could tie a bicycle-riding Smith to the crime.

We're told Chasen was shot going westbound on Sunset, waiting to turn left onto Whittier Drive ... which would mean Smith would have been in the middle of the busy street on his bicycle when he allegedly fired the shots.