Mark Duggan was a member of a violent gang involved in gun crime and dealing class A drugs, a senior detective has told an inquest.
Det Ch Insp Mick Foote headed Operation Dibri which targeted Tottenham gang TMD, a group he said contained "48 of Europe's most violent criminals".
Mr Foote told the hearing: "Duggan was in the group of 48."
Mr Duggan, 29, was shot by police in Tottenham, north London, in August 2011, sparking riots across England.
Mr Foote told the inquest into Mr Duggan's death that in January 2011 the Metropolitan Police received intelligence that Mr Duggan had shot "someone in a nightclub" and in February 2011 that he had "fired shots in club car park".
Police had Mr Duggan under "lifestyle surveillance" and later in 2011, officers received intelligence he "had taken possession of gun", said Mr Foote, who was called as the first witness at the inquest.
However, the police "had no specific intelligence to arrest Duggan before 4 August", the day he was shot dead, the jury heard.
At the inquest, the jury was shown police paperwork suggesting Mr Duggan and his associates had been "directly responsible for murders".
A form quoting police intelligence said 10 shootings and two murders were linked to the TMD gang.
A police intelligence form said Mr Duggan "was violent" and had "aggressively confronted" police on the Broadwater Farm estate in north London.
Mr Duggan had convictions for cannabis possession, handling stolen goods and had been cautioned for public disorder, jurors heard.
The inquest at the Royal Courts of Justice is expected to last two months.