London's Metropolitan Police have identified the man and woman killed in Friday's terrorist attack as Jack Merritt, 25, and Saskia Jones, 23. Both were participating in the University of Cambridge's Learning Together prisoner education event at Fishmongers' Hall where Usman Khan launched his fatal stabbing attack.

Both Merritt and Jones were graduates of the University of Cambridge. The school said another stabbing victim, whose identity has not been publicly released, was a staff member.

Merritt was a course coordinator for Learning Together and Jones was a volunteer, the school said. The program, launched in 2014, works to educate prisoners alongside undergraduate university students.

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Merrit's family described him as "our beautiful, talented boy" and said he "died doing what he loved."

"He lit up our lives and the lives of his many friends and colleagues, and we will miss him terribly," his family said in a statement." Jack lived his principles; he believed in redemption and rehabilitation, not revenge, and he always took the side of the underdog."

Merritt's family said he was, "looking forward to building a future with his girlfriend" and wanted a career helping people in criminal justice.

Jack Merritt, 25, left, and Saskia Jones, 23. Courtesy of Met Police

"We know Jack would not want this terrible, isolated incident to be used as a pretext by the government for introducing even more draconian sentences on prisoners, or for detaining people in prison for longer than necessary," his family said in a statement.

Jones' family described her as being "intent on living life to the full and had a wonderful thirst for knowledge."

"Saskia was a funny, kind, positive influence at the center of many people's lives," her family said in a statement. "She had a wonderful sense of mischievous fun and was generous to the point of always wanting to see the best in all people."

Her family said she had a "great passion for providing invaluable support to victims of criminal injustice." She was applying for a police graduate recruitment program, wishing to specialize in victim support, her family said.

According to police, Khan, 28, was attending the Learning Together event when he began his deadly attack. Sentenced to prison in 2012 on terrorism charges, Khan was released in December 2018 and was on probation. According to British media, Khan agreed to wear an electronic monitor.

Neil Basu, London Police's counterterrorism chief, said Khan was wearing a "hoax explosive device." Bystanders — wielding a fire extinguisher and what reports say was a narwhal tusk — chased after Khan. Videos from the scene showed a group of bystanders spraying fire retardant at the knife-wielding attacker and pinning him on the ground until police arrived. Police then shot and killed him.

Three other people were stabbed in the attack. Two remain hospitalized while one has already been released, police said.

Audrey McNamara contributed to this report.