Semone Wilson, a 29-year-old woman reported to be Duggan's fiancee, told several news outlets she had received a text message from Duggan approximately 15 minutes before the shooting, in which he said the "Feds" were following him.
Close relatives of Duggan provided a glowing description of Duggan, father to four children.
"He was a good man. He was a family man," one relative told London's The Guardian.
Wilson told Channel 4 News Duggan was not the gangster he had been described to be and said she knew Duggan would not have fired on police.
"They portray Mark as a gangster but he's not known to any gangsters or gangs," Wilson said. "Don't get me wrong, he's well known, very popular, but he's not a gangster. He's a loving caring guy."
But both Duggan's Facebook page and other media reports allegedly show connections between Duggan and a well-known London gang, according to The Guardian.
The Voice, Britain's leading black newspaper, wrote that Duggan and his best friend both were "linked" to Tottenham's Star Gang. Still, according to The Voice, friends described Duggan and his friend as "fun-loving party boys" who were well-known in London's rave scene, but not hardened gangsters.
"Let me put it this way, Mark was the kind of guy who would know better. He was a road guy, he knows you don't shoot at the police," one friend said.
Scotland Yard declined to comment on Duggan's alleged criminal history.