The last two boys died three weeks apart. On February 4, 1994, David Hanson, fifteen, was killed at a house on Roker Terrace in Sunderland, and his body was set alight; it was found on February 8. On February 25 David Grieff, also fifteen, was killed on a derelict allotment in Fulwell, about fifty yards from the shed where Thomas Kelly, eighteen, had been strangled and burned on November 26, 1993. All three had been pupils or former pupils of Monkwearmouth School, and the suspicion among police and among the school's own staff and pupils was that they had known the man who killed them.
Steven John Grieveson was arrested on March 11, 1994, and at first the charge was an attempted burglary, at the same Roker Terrace house where Hanson's charred body had been found. He was twenty-three, born in Sunderland on December 14, 1970, and had gone to school mainly at Hylton Red House rather than Monkwearmouth. The murder charges took another twenty months of investigation and were brought in November 1995.
He was called the Sunderland Strangler, for the city and for the method, which was ligature strangulation. The fires were meant to destroy evidence, and the trial judge said so: he told Grieveson he had found an efficient and effective way to kill Thomas Kelly and hide what he had done by setting fire to the body, and that far from being appalled by it, when the chance came to repeat the experience he did it again. Accounts of the case describe him choosing vulnerable boys, several of them solvent users, and leaving scenes that could be read as accidental deaths from glue sniffing or fire. For a time they were read that way, and the deaths were not connected despite how much the victims and circumstances had in common.
The trial at Leeds Crown Court lasted six weeks. The court accepted that he had killed the three boys to keep his homosexuality hidden. On February 28, 1996, the jury convicted him of all three murders, the public gallery erupted, and he received three life sentences with a recommendation that he serve at least thirty-five years before the Home Secretary considered release. Thomas Kelly's father said it was a great relief that "this monster is off the streets so no other family will have to go through what we faced."
There had been an earlier boy. Simon Martin, fourteen, was found dead on May 26, 1990, in Gilside House, a derelict property in Roker, with blunt injuries to the head. His killing stayed unsolved, and for more than a decade it left suspicion hanging over an innocent man. Detectives questioned Grieveson about it at Full Sutton in November 2000, and he denied it. In June 2004 he wrote to the Victim Liaison Service admitting the three murders of 1993 and 1994, and left Simon out, so he was not charged.
In a police interview in January 2012 he finally admitted it. The jury at his second trial heard that he said he had gone to Gilside House with Simon after they had played football together in May 1990, and that the killing had haunted him for years. He was charged on November 22, 2012. On February 11, 2013, he accepted responsibility for the death but denied murder, arguing diminished responsibility and saying it had not been planned. On October 24, 2013, after a nine-day trial at Newcastle Crown Court, the jury convicted him of murder, and he received a fourth life sentence, twenty-three years after the boy died.
Outside the court Simon Martin's father read a statement for his family, his wife and his son who was no longer alive. Speaking for all four families, he said their sons had been taken by a cruel man whose actions cost four boys their lives, and that they were innocent boys whose own actions had in no way led to their deaths.
On February 20, 2014, Grieveson was arrested again, on suspicion of the 1992 murder of Nikki Allan, a seven-year-old girl found stabbed and beaten in a disused warehouse in Sunderland that October. A neighbor who had confessed to her killing had been acquitted in 1993 after the court found the police had used oppressive methods to question him, and the head injuries in her case resembled those Simon Martin had suffered. Detectives questioned Grieveson and later said he faced no further action. In 2017 police isolated a full DNA profile of her killer from old samples, and in May 2023 David Boyd, a convicted sex offender whose partner had babysat for Nikki, was found guilty of her murder.
Grieveson is held at HMP Full Sutton in the East Riding of Yorkshire.