London, Jan 25 : A 32-year-old man who stabbed British-Indian teen, Grace O'Malley-Kumar, and two others to death in the UK last year, will not face trial for murder after his plea of guilty to manslaughter was accepted as victims' families grieved the loss of lives. Valdo Calocane, a dual Guinea-Bissau/Portuguese national, killed 19-year-old students, Grace and Barnaby Webber, and 65-year-old school caretaker Ian Coates during an incident near Nottingham University on June 13, 2023. During Tuesday's hearing at the Nottingham Crown Court, prosecutors accepted Calocane's guilty plea based on diminished responsibility after psychiatrists said he suffered paranoid schizophrenia. The decision was made as Calocane suffered from "serious" mental illness, a judge was told. Also known as Adam Mendes, Calocane, who "believed MI6 was spying on him", denied three counts of murder but admitted three counts of manslaughter based on diminished responsibility in November, 2023. Prosecutor Karim Khalil KC told Nottingham Crown Court on Tuesday that the victims' families -- who had hoped for a murder trial -- were consulted before deciding to accept the pleas entered by Calocane. The court was told that Grace showed "incredible bravery" by attempting to fight off Calocane and save Webber as they were attacked while walking home from a night out. Calling Calocane "a cold, cowardly and calculating killer", Grace's father, Sanjoy Kumar praised his daughter who "heroically and valiantly fought you. Like a hero, she put herself in harm's way," The Guardian reported. "You deserve the harshest punishment available. A clear message must be sent out to the families in our country. They must be reassured that their children are safe ... and that something like this never happens again," Kumar told the court. Calocane will also be sentenced for three counts of attempted murder after he tried to run over three pedestrians with a van on the same day he killed Grace, Webber, and Coates, local media reports said. The CCTV footage played in court showed Calocane walking calmly just hours before the attack, carrying a rucksack and a holdall, later found to contain multiple weapons. After the first killings, Calocane called his brother and told him to take the family out of the country. When asked: "Are you going to do something stupid?", Calocane replied: "It's already done." According to witnesses, they heard "an awful, blood-curdling scream" and saw Grace crawl towards the houses on the opposite side of the road shouting for help. The Guardian reported that Calocane had been receiving mental health treatment since 2020, which included being treated with antipsychotic medication. Prosecutor Khalil said Calocane, who came to the UK at the age of 16 with his family in 2007 and earned a mechanical engineering degree at Nottingham University, 'actively concealed symptoms of psychosis' and refused to take his medication. In 2020, he was admitted to the hospital after breaking down two doors to different apartments in his block, and a year after, he assaulted a police officer during a search of his flat in which a bag of unused medication was found. Calocane, who is now scheduled for a two-day sentencing hearing, may face life imprisonment or a hospital order. /IANS