The first victim of the London Bridge terror attack to be named has been praised by his father as "a beautiful spirit".
Jack Merritt, 25, was one of two people stabbed to death by Usman Khan during the convicted terrorist's rampage on Friday.
Khan, 28, was shot dead on the bridge, while wearing a fake explosives vest, by police.
Merritt, a course co-ordinator at Cambridge University's criminology institute, was killed as he helped host an event near London Bridge to mark five years of a prisoner rehabilitation programme.
It was targeted by Khan, a former participant, who arrived armed with two knives.
"I am sad beyond words to report that a course co-ordinator, Jack Merritt, was killed," Stephen Toope, Cambridge University vice-chancellor, said in a statement.
"Our university condemns this abhorrent and senseless act of terror."
He added that a woman killed in the stabbing spree, who has yet to be named, was a former student, while one of three people injured was a member of its staff.
Merritt was reportedly a Cambridge University graduate who was working for its "Learning Together" initiative run by the Department of Criminology to promote prison-based education.
"He was an exceptional young man, and I'm only finding out the half of it now he's gone," David Merritt, the victim's father, said in a series of messages on Twitter.
"I talked often with Jack about Learning Together & I was inspired by the stories he told me," he added.
Khan had participated in the programme while serving some of his 16-year sentence for terrorism offences at Whitemoor prison in Cambridgeshire, eastern England.
He was conditionally released from jail last December under so-called licensing conditions after serving around half of his jail term.
That has caused a political storm in Britain, which is in the grip of election campaigning ahead of voting on December 12.
Prime Minister Boris Johnson - whose Conservatives have been in power for nearly a decade - is now vowing to end the practice and stiffen sentences.
David Merritt has criticised that response, writing in one social media message: "We don't need knee-jerk reactions."
In another post subsequently deleted, he said his son "would not wish his death to be used as the pretext for more draconian sentences or for detaining people unnecessarily."
It also described him as "a beautiful spirit who always took the side of the underdog".