Vassil Patilov, a defendant in a murder and drug distribution trials, was shot dead while parking his business car on a central crossroad in downtown Sofia late on Wednesday.
The victim, 34, was badly injured at the head and the body by the bullets fired by unknown shooter.
Patilov died on his way to Pirogov Emergency Institute.
According to initial reports, the killer was accompanied by another man at the time of the incident but only he shot at the luxurious Mercedes.
The name of Vassil Patilov hit the headlines in September 2001 when he was arrested along with 10 other criminals during a search of the house of the Roma drug boss Kiril Kirilov, dubbed the Japanese.
Except murder and drug distribution charges, the victim faced also robberies and blackmail accusations.