A man who plied his partner with cocaine and then fatally strangled her on the night she tried to leave him has been found guilty of murder.

Kieron Goodwin, 33, was convicted on Thursday at Bristol Crown Court of killing Olivia Wood in his flat in Frome, Somerset, on 30 July last year.

The jury heard that Goodwin had quickly turned controlling during their three-month relationship, and Ms Wood had been “deeply unhappy”. On the night she died, she had packed her belongings into a suitcase and rucksack, suggesting she was preparing to leave, the court was told.

Judge Martin Picton thanked the jury for their work on an “utterly harrowing” case.

Goodwin was also convicted of a string of sexual offences including four counts of rape against three other women.

He previously pleaded guilty to four counts of coercive control relating to Ms Wood and three other victims.

Ms Wood, an ecologist based in Liverpool, was described by her employer as “hard working and professional”, who was “highly thought of by her colleagues”.

In a tribute to her after Goodwin’s conviction, Ms Wood’s family said: “The pain our family is feeling is indescribable.

“Olivia was the glue that held us together, a loyal friend, a devoted sister, a cherished daughter.

“She was a rarity – profoundly selfless, disarmingly witty, a timeless beauty. Always there to make a cup of tea when someone looked in need, to listen, to help.

“Now she has been taken from us and we are left with a chasm in our lives, a love that can never be replaced.”

Ms Wood never formally moved to live with Mr Goodwin but spent a lot of time with him in Frome.

Goodwin quickly turned controlling and over the course of their short relationship she transferred more than £6,000 to him – much of which was spent on his cocaine habit.

He also pressured her into having sex with another man and performing sex acts on camera against her will, WhatsApp messages between them showed.

Shortly before her death, Ms Wood rang her employer to say she needed to take some time off because of her partner’s mental health and that he was threatening to kill himself.

Ms Wood never spoke to anyone about the situation she was in, the jury heard, but notes on her phone revealed she was “deeply unhappy”.

Messages from the defendant’s phone revealed he was buying cocaine almost every day, and he was sending her out to collect the drugs.

Mr Goodwin called 999 at 2:50 BST on 30 July to say Ms Wood was not breathing and he was given instructions in first aid.

But during the call he was simultaneously deleting hundreds and photos of videos from his phone.

Prosecutor Adam Vaitilingam KC told the jury they might find it “troubling” that a man trying to save someone’s life decided “he needs to delete potentially incriminating material from his phone”.

Paramedics told the court they spotted a big bruise developing on Ms Wood’s neck and Mr Goodwin told them: “I’ve killed her. It’s all my fault. Oh my god, is she going to die? What have I done?”

A post-mortem examination revealed Ms Wood had a potentially fatal level of cocaine in her system, and the hyoid bone in her neck was fractured – an injury often associated with fatal neck compression.

The pathologist also found bruising in the shape of parallel lines to her neck, consistent with a belt of about 3cm in width.

The prosecutor said that the strangulation, in addition to the cocaine, “played a large part” in Ms Wood’s death.

Goodwin has never given an explanation for Ms Wood’s death, and did not give evidence at trial.

But toxicologist Dr Stephen Morley, giving evidence for the defence, said the levels in the victim’s blood were “three times what toxicologists would be comfortable with”, describing them as “likely to be fatal”.

He added: “There is no single concentration where you can definitively say death will occur.”

Other victims told police, Goodwin had pressured them into taking cocaine when they had no history of drug abuse, including by injection.

One told the jury she believed the defendant wanted her to take drugs in order to make her more “malleable”.

Goodwin was further convicted of five counts of causing a person to engage in sexual activity without consent, one count of assault by penetration and one of intentional strangulation.

The date for his sentence has yet to be set.

Senior investigating officer Det Supt Lorett Spierenburg, of Avon and Somerset Police, said: “Kieron Goodwin is an incredibly dangerous and manipulative man who will now face justice for the horrendous crimes he subjected these women to.

“His offending has had a significant impact on each of them and ultimately – and tragically – had fatal consequences for Olivia.

“Each of those women who have spoken so bravely about what they suffered at his hands deserves enormous praise.

“I also want to take this opportunity to pay tribute to Olivia’s family and friends who have acted with such dignity, despite Goodwin’s cowardice in refusing to admit his crimes and provide them with the answers they deserve about what happened that night.”