Carl Campbell, 33, suffered a gunshot wound to the head and was pronounced dead in his stationary Ford Fiesta on Tuesday.
Two men have been charged on suspicion of Campbell’s murder.
But it emerged today the victim was locked up for six years in 2009 after admitting causing death by dangerous driving and attempting to pervert the course of justice.
Reckless Campbell, then 26, ploughed down great-granddad Clarence Elwin, 92, in Tipton, West Mids, in June 2008 — and tried to cover his tracks by claiming his car was stolen.
Mr Elwin, known as Joe, was walking his beloved Yorkshire Terrier Zach when he was struck at about 50mph.
The retired rail worker died some five months later, having battled multiple injuries.
Mohammed Humza, 19, and 24-year-old Vikesh Chauhan, both of no fixed address, will appear at Wolverhampton Crown Court tomorrow to face murder charges.
Campbell was gunned in an attack in West Bromwich, West Mids, at around 2.30pm.