Jealous husband jailed for 23 years after stabbing wife to death

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

Thisara Weragalage, 38, admitted murdering his wife, Niwunhellage Dona Nirodha Kalpani Niwunhella, known as Nirodha, 32, outside her boyfriend’s address in Cardiff last year.

The defendant and Ms Niwunhella had been living separately for several months before the attack, and the court heard he was “obsessed” with Ms Niwunhella and her new partner, James Stephenson.

Sentencing Weragalage at Cardiff Crown Court on Friday, Judge Daniel Williams said his “brutal selfishness” had cut Ms Niwunhella’s life short.

The court heard Weragalage and Ms Niwunhella had married in Sri Lanka in 2017 and moved to the UK in 2022.

Ms Niwunhella found a job at the Springbank Care Home in Barry, where she met and developed a friendship with her colleague James Stephenson.

As they grew closer, she confided in Mr Stephenson that she was having issues in her marriage, telling him her husband was physically abusive and they were having “sexual issues”.

Weragalage became increasingly jealous after he discovered messages between Ms Niwunhella and Mr Stephenson on her phone, 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, at which point Ms Niwunhella and Mr Stephenson began a romantic relationship.

The court heard Weragalage begged Mr Stephenson and Ms Niwunhella’s father to help him repair his marriage, and began to threaten the couple as his desperation deepened.

Judge Williams said: “You could not accept that your marriage was at an end… Nirodha’s relationship with James Stephenson became your sole and obsessive focus.

“A message found on Nirodha’s phone, sent by her to a friend on July 10, said that you were threatening to kill her and James Stephenson.”

The court heard Weragalage visited Mr Stephenson’s address on eight occasions before the attack, and purchased a pack of kitchen knives the day before he murdered his wife.

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

The court heard Ms Niwunhella suffered “extensive and catastrophic” injuries in the attack by her husband, including 17 stab wounds and injuries to her neck, face, chest and leg.

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 under a lorry later that morning.

The court heard the defendant told police he could not remember what happened after he confronted his wife, and said he only bought the knives in order to scare her.

Andrew Taylor, defending, said: “He was obsessed by his wife and he was overtaken by jealousy.

“He could not live without her and he could not contemplate a future where he was on his own.”

Weragalage was jailed for a minimum 23 years and nine months at Cardiff Crown Court on Friday, after pleading guilty to murder and possession of a knife in a public place.

Judge Williams described a “ferocious attack” that Ms Niwunhella had “no chance of surviving”.

He said: “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.”

Emma Davies of the Crown Prosecution Service said: “Thisara Weragalage planned his attack, visiting the area several times leading up to it and buying the murder weapon.

“His premeditation was a significant factor in this shocking murder.

“The strong evidence presented by the Crown Prosecution Service demonstrated his intention and resulted in a guilty plea.

“The Crown Prosecution Service are working together with the police to build strong cases against those who perpetrate violence against women and girls, and our prosecutors are making sure more victims of these abhorrent and devastating crimes receive the justice they deserve.

“Our thoughts remain with the family and friends of Nirodha, who have suffered a tragic loss.”

For more information on the signs of domestic abuse go to What is domestic abuse? | South Wales Police. Find links to local support in your area here Support organisations for victims of domestic violence | South Wales Police