The families of the three people stabbed to death in the Nottingham attacks last year have welcomed a court of appeal review of the “unduly lenient” sentence of the perpetrator, Valdo Calocane. The killer was sentenced to an indefinite hospital order last month for the attacks on university students Barnaby Webber and Grace O’Malley-Kumar, both 19, and a school caretaker, Ian Coates, 65, in the early hours of 13 June last year. He had pleaded guilty to manslaughter of the three people on the grounds of diminished responsibility, and to the attempted murder of three other people, one of whom was so severely injured he needs a permanent carer. The attorney general, Victoria Prentis, said she would refer the sentence for reconsideration after receiving a number of referrals under the unduly lenient sentence scheme, which allows members of the public to request a review of any sentence they think is not severe enough. In a joint statement, the families said: “We were very glad to hear that the attorney general has agreed with us that the sentencing given to Valdo Calocane, who so viciously and calculatedly killed our loved ones, was wrong. “We are optimistic that when this reaches the Royal Courts of Justice for its appeal there will be an outcome that provides some of the appropriate justice that we have been calling for.” During the sentencing hearing in January, O’Malley-Kumar’s father, Dr Sanjoy Kumar, told Calocane he was a “a cold, cowardly and calculating killer”, and praised his daughter who “heroically and valiantly fought you. Like a hero she put herself in harm’s way.” Webber’s mother, Emma Webber, said she had “utter rage and pure hatred” for her son’s killer, while Coates’s son described Calocane as “a selfish monster who decided to go on a spree killing”. Announcing the review, Prentis said: “Valdo Calocane’s crimes were horrific and have shocked a nation. He brutally killed three innocent people, and violently attacked three other victims. Their experiences will stay in our minds for a long time to come. “This was a case that evoked strong feelings amongst so many people and it was no surprise that I received so many referrals under the unduly lenient sentence scheme to consider the hospital order handed to Calocane. “My duty as a law officer in considering whether sentences may be unduly lenient is to act independently of government, even when it is not easy or popular. “Having received detailed legal advice and considered the issues raised very carefully, I have concluded that the sentence imposed against Calocane, for the offences of manslaughter by reason of diminished responsibility and attempted murder, was unduly lenient and will be referred to the court of appeal. “My thoughts remain with all of Calocane’s victims, as well as their families and friends, who have shown such immeasurable strength during this devastating time.”