Jealous man jailed for stabbing wife to death in Cardiff

A man has been jailed for at least 23 years for stabbing his wife to death after they separated and she started dating a colleague.

Thisara Weragalage, 38, admitted murdering his 32-year-old wife, Niwunhellage Dona Nirodha Kalpani Niwunhella, who was known as Nirodha, in Cardiff last year.

The defendant and Ms Niwunhella had been living apart for several months before the attack outside her boyfriend's home, and the court heard he was "obsessed" with her and her new partner, James Stephenson.

Weragalage and Ms Niwunhella married in Sri Lanka in 2017 and moved to the UK in 2022, Cardiff Crown Court heard.

Ms Niwunhella met and developed a friendship with colleague Mr Stephenson and as the pair grew closer she confided in him she was having issues in her marriage, telling him her husband was physically abusive and they were having "sexual issues".

After discovering messages between Ms Niwunhella and Mr Stephenson on her phone, Weragalage became increasingly jealous and began "spying" on her and trying to control who she socialised with, the court heard.

The marriage continued to deteriorate and in April 2025 the couple moved into separate addresses, and Ms Niwunhella and Mr Stephenson began a romantic relationship.

The court heard Weragalage began to threaten the couple as his depression deepened.

Weragalage visited Mr Stephenson's home on eight occasions before the attack, the court heard, and he bought a pack of kitchen knives the day before he murdered his wife.

Mr Stephenson was working a night shift when Ms Niwunhella left his home on the morning of 21 August 2025 and was ambushed by Weragalage in the car park outside.

Ms Niwunhella suffered "extensive and catastrophic" injuries, the court heard, including 17 stab wounds and injuries to her neck, face, chest and leg.

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Mike Jones KC, prosecuting, said: "The prosecution case is that such was the ferocity of the attack on her that the knife broke during the assault.

"His intention, the crown say, was a determined and planned intention to kill her."

Weragalage fled the scene and was detained after trying to throw himself underneath a lorry later that morning.

He told police he could not remember what happened after he confronted his wife and claimed he only bought the knives to scare her, the court heard.

Judge Daniel Williams said Ms Niwunhella had "no chance of surviving" the "ferocious attack"

He added: "She has been described as the kindest and most caring person you could meet.

"She had a long and happy future ahead of her. Your brutal selfishness has left a void which can never be filled."

Weragalage was jailed for a minimum of 23 years and nine months after pleading guilty to murder and possession of a knife in a public place.

(c) Sky News 2026: Jealous man jailed for stabbing wife to death in Cardiff