Azelle Rodney "would still been alive today" if the police officer responsible for shooting him dead had stopped after the third shot, a public inquiry heard.
Leslie Thomas, counsel for the family of Rodney said "had E7 (the officer) stopped after shots one, two, three, it is probable that [he] would still be alive today."
Instead Leslie says that the officer went on to discharge a "breath-taking" five further shots, two hitting the top of his skull.
The 24-year-old was shot a total of eight times and died within seconds when the officer shot into the car in which he was travelling.
Police alleged that he and other suspects on their way to carry out a drugs-related robbery when police stopped the car they were in on a busy street in Harlesden, north west London.
Speaking on behalf of the police officer that inflicted the fatal blow, QC Samantha Leek argued that it was not possible to decide which shot to stop at. She said that it is not possible to stop and check to "see if a person is still a threat."
In the closing speech of the inquiry that has lasted 10 weeks, almost 8 years after Rodney's death, Thomas said that the facts of the case are "stark and chilling."
The hearing held earlier today, at Principal Registry of the Family Division in High Holborn, London heard all parties give speeches on their closing submissions.
Thomas told the hearing that the police had "failed" to properly manage the incident and outlined a list of faults, including failure to carry out a risk assessment of the possible dangers.
He also said that police did not give Rodney the right to surrender before he was shot. He said that had he been given that right, he would "almost certainly" be alive today. This he said was a mark of "extraordinary failure of the operation to arrest him."
The inquiry, which started in September replaced an inquest that was due to be held because a coroner was unable to see some of the evidence police say were behind their decision to carry out the operation.
Speaking on behalf of the family, Thomas said Rodney's relatives had been left "emotionally scarred" from his death.
Closing his speech he said it is their wish that justice be served so that Rodney's death will "not be in vain."
The family are now awaiting a verdict from the inquiry's chairman Sir Christopher Holland.