On 4 August 2011 my brother Mark Duggan was shot dead by police after the minicab he was travelling in was pulled over by officers. Two days after the shooting, riots began in Tottenham, which spread to other parts of England. It is more than two years since I lost my brother, but we are no nearer to finding out what happened on the day Mark was killed and why. On Monday an inquest opens at the Royal Courts of Justice. Its stated purpose is to bring to light the full facts surrounding Mark's death.

As a family we had no experience of what was to come after we lost Mark. We were promised a full and independent investigation into the circumstances surrounding the shooting, but to date, we know little more than we did when the tragedy happened. We have had many meetings with the Independent Police Complaints Commission, but as far as I'm concerned all those meetings have been a waste of time. We have just been fobbed off. If Mark had been killed by anyone other than a police officer we would be much further down the road by now of knowing what happened. It has been reported that the IPCC inquiry, whose findings we've not been allowed to see, has exonerated the police officers involved in the shooting. Yet the IPCC did not interview those police officers.

Instead of being kept informed about the investigation we have had to deal with hostility and abuse from members of the public because of the way the shooting was initially reported in the media and the subsequent riots. It was first reported as a shootout, and by the time that statement was retracted – Mark never fired a shot – the idea was fixed in people's minds that he had done so.

The family attended a peaceful demonstration at Tottenham police station two days after Mark's death, trying to find some answers about why he had been killed. Family members were not involved in the subsequent rioting in Tottenham and beyond yet many blamed us for them. I felt as if we were the most hated family in Britain. Readers of some newspapers posted online comments underneath articles about the case referring to us as monkeys. We encountered so much racism.

We watched the trial of Kevin Hutchinson-Foster, who was convicted of supplying a weapon to Mark and jailed for 11 years. At times Kevin's name was barely mentioned. The whole of the trial seemed to be about Mark, yet there was no defence team to put my brother's side of the story in court.

Since Mark was killed we have lost faith in the police, the judiciary and the IPCC. We never expected it to be easy to find out the truth about what happened to Mark but we also never expected it to be this difficult, and we never imagined it would take more than two years. I don't know how we've got through it. As a family we have remained calm and dignified but at times we have wanted to scream. Fortunately we have had good advice and support during this time. Otherwise I think that we all would have had mental breakdowns from the strain.

Mark never got the chance to put his case. He was shot dead before he could do that. We feel that in our search for the truth we are not only taking on the entire Metropolitan police service but the government too. We know Mark can never be back with us but it doesn't mean we will give up the fight to get the truth. The Metropolitan police say they are making London safer but they didn't make it safer for Mark, and they didn't make it safer when the riots began.

We continue to live with the loss of Mark and the impact on our family will be lifelong. Although we no longer trust the police and the IPCC we do trust the inquest system. We are going into this inquest hoping that at last we will find out the truth about what happened to Mark, that those responsible will be held to account, and that what happened to Mark will not happen to anyone else in the future.

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