An inquest jury concluded that police lawfully killed a man whose shooting in 2011 sparked deadly riots across the country.
Family members and supporters of Mark Duggan shouted obscenities and smashed a door after the decision was read out at the Royal Courts of Justice in London.
The 29-year-old father of six was gunned down after police stopped the taxi in which he was travelling in Tottenham, north London, in August 2011.
The resulting unrest in London and other cities left five people dead and caused millions of pounds worth of damage.
"We will still fight for justice," his brother Shaun Hall said outside the court, to chants of "No Justice" from other supporters.