We're told cops are interested in the road rage theory as it relates to the suicide of the man last night who was the object of a search warrant connected to the murder.
TMZ has learned ... the man who shot himself in the head is HAROLD MARTIN SMITH.
Although there are reports Smith is a suspect in the murder of Ronni Chasen, we're told that label is based on LAPD sources, and the Beverly Hills PD is only considering him a person of interest.
Nevertheless, sources tell us the BHPD is actively investigating Smith to determine if he was in the Beverly Hills area the night of the murder.
And, we're told, as far as Smith goes, money was not the motive. Although Smith talked about getting $10,000, we're told that was in connection with a civil lawsuit.
So far, we're told, there's no physical evidence linking Smith to the killing, but cops are actively investigating.