Cyrena Barned said outside court that she was pleased with the 31-year sentence received by Dean Smith, for the murder of her brother Aarron McKoy.
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The fatal collision happened in Hackney, east London, just before midday on Tuesday.
Police are hunting three youths in connection with the incident which happened on January 4 in Romford.
Made In Chelsea star Mark-Francis Vandelli has become the fourth celebrity to withdraw from the winter sports programme.