Teenager found guilty after killing woman whilst high on laughing gas in Bermondsey

A 16-year-old boy has been found guilty of killing a woman during a row after they both inhaled laughing gas last Christmas Eve.

The youth, who cannot be identified, had rowed with Kacey Clarke, 22, and stabbed her in the chest in a flat in Bermondsey, south-east London.

Earlier that evening he was caught on CCTV threatening to “ching” her up and kill her, the Old Bailey heard.

Like the victim, the boy was said to have a history of inhaling nitrous oxide – commonly known as laughing gas – which was classified a class C drug in November 2023 in a crackdown on anti-social behaviour.

A search of the defendant’s bedroom revealed a large collection of canisters, a jury was told.

After the killing, the youth hid the weapon – a large knife – in a railway arch where it was later discovered by a Thames Water workman on 17 January.

The court heard he had a history of possessing knives, having been caught with a 25cm long Rambo-style blade in an ice cream shop and a lock knife in his waistband in a residential area.

In all, he had convictions for 25 offences between April 2022 and September 2023 and was subject to an electronically monitored tag at the time of Ms Clarke’s death.

The crimes were mainly for theft and handling stolen goods and included an incident in April 2023 when he snatched a mobile phone from a woman who was injured when they both fell over, the court was told.

The defendant denied Ms Clarke’s murder in a row sparked by the loss of her car keys.

Giving evidence, the boy admitted that he had taken laughing gas and claimed he had acted in self defence.

A jury at the Old Bailey deliberated for 13 hours and 23 minutes to find the boy guilty of manslaughter.

Moments before, the defendant had flashed a smile at family members from the dock as he was cleared of the more serious charge of murder.

Judge Simon Mayo KC ordered pre-sentence reports and said he would sentence the boy at a later date.

Previously, prosecutor Jane Osborne KC had said the defendant had “lost his temper” with mother-of-one Ms Clarke.

The prosecutor said: “They might have been arguing, they might even have been fighting, but that argument met a fatal end when [the defendant] armed himself with a very large knife… and used it to stab [Ms Clarke].

“His intention to stab… is nowhere more evident than on the audio footage which records him shouting that he is going to ‘ching’ her up and kill her.”

Earlier that evening, Ms Clarke had texted a relative and told her she had been taking “balloons”, which was slang for inhaling nitrous oxide.

When challenged about it, Ms Clarke told the relative that she “shouldn’t be boring because it was Christmas”.

Another relative, texted to say Ms Clarke was “buzzin like nothing”, the court was told.

Police and paramedics were called just after 10pm and found Ms Clarke was lying on the kitchen floor of the Bermondsey flat with a single stab wound to the chest.

The defendant was arrested nearby around 45 minutes later.

He had been wearing Croc shoes and blood was found on his bare toe, jurors were told.

Clumps of his hair that appeared to have been ripped from the scalp were also recovered from the scene, the court heard.

A broken lamp and picture frame were found on the floor of the living room as well as a bag of the clothes believed to belong to the victim beside two large 640g nitrous oxide canisters, jurors were told.

In a police interview, the defendant offered a prepared statement in which he said Ms Clarke had become angry that she could not find her car keys.

She smashed a lamp and threw something at the defendant, hitting him on the side of the face, he said.

A fight ensued with Ms Clarke grabbing his hair, he claimed.

Ms Clarke then burst into a room holding a knife and the boy said he picked up a blade and waved it to create an “invisible shield”, the court heard.

He said he thought she was lying when she said she had been stabbed as he had no recollection of making contact, according to the statement.

Following the verdicts on Friday, the defendant was remanded into custody.

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