A lab assistant strangled his 23-year-old colleague before cutting her throat and dumping her body in woodland, while repeatedly sending messages to her phone saying she was “amazing” and that he loved her to throw police off the trail.
Ross McCullum, 30, met HR adviser Megan Newborough at the Midlands building materials company where they worked and killed her a month after the pair began an intimate relationship.
He has previously pleaded guilty to manslaughter but denies her murder.
At the opening of the trial at Leicester crown court on Tuesday, prosecutor John Cammegh KC said McCullum made a series of “devious and calculating attempts” to lay a false trail for investigators.
“The defendant embarked immediately upon a series of deliberate actions carefully calculated and executed to cover up Megan’s murder and his role in it,” he told the court.
“This behaviour conclusively exposes the fact that he was not momentarily struck by an irresistible wave of emotion or other disability of the mind, but that he was a cunning and resourceful murderer.”
He told the court that on the evening of Friday 6 August last year, Newborough travelled from her home in Nuneaton to McCullum’s house in nearby Coalville, which he shared with his parents who had gone out for the evening.
The prosecution said shortly after arriving, McCullum “strangled Megan with his bare hands”, before cutting her throat 14 times with a carving knife from the kitchen.
He later told police he did so “to make sure she was dead”.
McCullum then bundled her body into her own car just before he texted her phone with the message, “You are fucking amazing”, followed by a smiley face and three kisses.
He drove to nearby countryside and dumped her body in dense bracken and also threw her phone into some undergrowth, but made a “crucial mistake” by not switching it off, allowing Newborough’s worried family to track it to the area which was less than a mile from McCullum’s home.
He was arrested by police in the early hours of Sunday 8 August on suspicion of kidnap at which point he told police where Newborough was and admitted she was dead.
When her body was found, “her hair was so saturated in blood it appeared to officers she was redhead,” Cammegh said.
Jurors were shown hundreds of WhatsApp messages between the pair, many of which showed McCullum expressing “fears of sexual inadequacy”. During one sexual fantasy he made Newborough address him as “Lord Commander”.
The court heard McCullum had been diagnosed with ADHD two years prior to the killing, and was on medication for this, but in the weeks before Newborough’s death he stopped taking it as he believed it “hindered his sleep and sex drive”.
A supervisor at Ibstock Brick, where they both worked, said he was able to detect when McCullum had not taken his medication as he became “loud, snappy, inappropriate and vulgar”.
McCullum told police he strangled Newborough when she “attempted to touch him intimately” and she slapped him when he told her to stop.
He claimed his “loss of control was triggered by memories of sexual abuse” he had suffered when he was young, and he was afraid Newborough might tell her colleagues in HR about this abuse.
Cammegh said this was a “cynical self-serving lie told at Megan’s expense in order to concoct an excuse to avoid responsibility of murdering her”.
The trial continues.
