One of the two people stabbed to death in the London Bridge terrorist attack has been identified. Jack Merritt, a 25-year-old University of Cambridge graduate, was killed when Usman Khan, 28, started the attack Friday at a conference on prisoner rehabilitation at the north end of London Bridge. The BBC reports Merritt was a course coordinator for Learning Together, a rehabilitation program for prisoners, which was hosting the conference. Merritt’s father, David, said on Twitter that he was a “a beautiful spirit who always took the side of the underdog.”

“My son, Jack, who was killed in this attack, would not wish his death to be used as the pretext for more draconian sentences or for detaining people unnecessarily,” he added. A woman who died in the attack has not yet been named. Three others were injured.