Confronted by bystanders, including a Polish man brandishing narwhal tusk he had grabbed from the wall of Fishmongers' Hall, Khan was wrestled to the ground.
His father confirmed the death on Twitter, calling him a "a lovely spirit who always took the side of the underdog".
A woman who died in the attack - declared by officers as a terrorist incident - has not yet been named.
Oliver Kirk, a London based criminal barrister, tweeted that he had seen Mr Merritt speak at a lecture several weeks prior to his death.
ISIS has claimed responsibility for London Bridge terror attack which killed the two members of the public, and left another three injured on Friday afternoon, through its Amaq news agency reports.
Police also confirmed the suspect was already known to authorities, and was convicted in 2012 for terrorism offences before being released from prison on licence in December 2018.
Just before news broke of the suspect's previous conviction, Prime Minister Boris Johnson, who is seeking re-election on December 12, said criminals must be made to serve their sentences.
"And it was while he was subject to these conditions that he performed this horrific attack yesterday", Fisher said.
Police said they are not actively seeking any other individuals connected to Saturday's attack, and have confirmed that it was being investigated as a terrorist incident.
Several British media outlets reported that he was wearing an electronic ankle bracelet at the time of Friday's attack.
Friday's attack has raised hard questions for the United Kingdom government and security services.
Forensic workers attend the scene on London Bridge in London, Saturday, Nov. 30, 2019.
Jack Merritt was the course co-ordinator for Learning Together, the education initiative run by the University of Cambridge's Institute of Criminology. Videos of the attack posted online show Khan being sprayed by a fire extinguisher as another man jabs forward with the tusk.
"This programme [Learning Together] was hosting the conference at Fishmongers Hall that was targeted by Khan ... who a participant at this conference", Challands said.
A BBC reporter on the bridge at the time said he saw what appeared to be a fight between a group of men, heard two shots and saw a man "prone" on the ground.
Queen Elizabeth II said she and husband Prince Philip had been saddened to hear of the attack and expressed her "enduring thanks" to the "brave individuals who put their own lives at risk to selflessly help and protect others".
"Being stabbed didn't stop him giving him a beating". "The long, monitored, discussions of Usman Khan about the madrassa (training camp) and his attitudes towards it and terrorism are highly eloquent of the seriousness of their objective", the judge said. The campaign, which has focused on the U.K.'s planned withdrawal from the European Union, was briefly suspended after the attack as Mr. Johnson returned to London, but resumed Saturday.