A furious husband who stabbed his “beautiful” ex-wife after she started dating a coworker has been sentenced to at least 23 years in prison.
Thisara Weragalage, 38, waited for his ex-wife Nirodha Niwunhella, 32, to leave her new boyfriend’s house for work before stabbing her to death on a quiet street in Cardiff.
Before the attack, the couple had been living apart for a few months. This was because Ms. Niwunhella had left Weragalage and started dating a coworker.
Cardiff Crown Court heard that Weragalage and Ms. Niwunhella got married in Sri Lanka in 2017 and relocated to the UK in 2022.
Ms. Niwunhella got a position at the Springbank Care Home in Barry, where she met James Stephenson, a coworker, and they became friends.
As they got to know each other better, she told Mr. Stephenson that her marriage was not going well and that her husband was physically abusive and they were having “sexual issues.”
The court heard that Weragalage grew more and more envious after finding texts between Ms. Niwunhella and Mr. Stephenson on her phone. He then started “spying” on her and trying to restrict who she hung out with.
The marriage got worse, and in April 2025, the couple moved into different homes. This is when Ms. Niwunhella and Mr. Stephenson started dating.
Thisara Weragalage, 38, waited for his ex-wife, Nirodha Niwunhella, 32, to leave her new lover’s house for work before stabbing her to death on a quiet street in Cardiff.
Before the attack, the couple had been living apart for a few months. Ms. Niwunhella left Weragalage (in the image) and started dating a coworker.
Weragalage was sentenced to at least 23 years and nine months in prison on Friday at Cardiff Crown Court. He had pleaded guilty to murder and having a knife in a public place.
The court heard that Weragalage became “obsessed” with Ms. Niwunhella and her new partner. He implored Mr. Stephenson and Ms. Niwunhella’s father to help him fix his marriage, and as his desperation grew, he started to threaten the couple.
The court heard that Weragalage went to Mr. Stephenson’s house eight times before the attack and bought a set of kitchen knives the day before he killed his wife.
Ms. Niwunhella left the address in the morning of August 21, 2025, while Mr. Stephenson was working a night shift. He was attacked in the parking lot outside.
She was found dead on August 21 last year, lying between two cars in Riverside, Cardiff. The community was “shocked and saddened” by the incident.
Judge Daniel Williams said that Weragalage’s “brutal selfishness” had cut Ms. Niwunhella’s life short when he sentenced him at Cardiff Crown Court on Friday.
The court observed, “You couldn’t accept that your marriage was over.”You couldn’t understand that Nirodha was making her own decisions to live without you.You grew completely obsessed with Nirodha’s relationship with James Stephenson.A text message from Nirodha to a friend on July 10 indicated that you were going to kill her and James Stephenson.
The court heard that Ms. Niwunhella’s spouse attacked her and caused “extensive and catastrophic” injuries, including 17 stab wounds and damage to her neck, face, chest, and leg.
“The prosecution’s case is that the attack on her was so violent that the knife broke during the attack,” said Mike Jones KC.
The crown says that he plotted and intended to kill her.
He further informed the court, “Nirodha’s murder was not a chance meeting between her and the defendant.”Instead, the defendant had been plotting his deadly attack on Nirodha because she had plainly moved on from their relationship and how he had treated her.
After Ms. Niwunhella died, her family posted a memorial that called her a “cherished daughter, family member, and dear friend to many.”
Weragalage ran away from the scene and was arrested after trying to dump himself under a truck later that morning.
The defendant told the police that he couldn’t recall what happened after he confronted his wife. He also indicated that he simply bought the knives to intimidate her.
Andrew Taylor, who was defending, stated, “He was obsessed with his wife and jealousy took over.”He couldn’t imagine a future without her and couldn’t live without her.
On Friday, Cardiff Crown Court sentenced Weragalage to at least 23 years and nine months in prison for murder and having a knife in public.
Judge Williams said that Ms. Niwunhella had “no chance of surviving” a “ferocious attack.”
He remarked, “People have said that she is the kindest and most caring person you could ever meet.”She has a long and happy life ahead of her.Your cruel selfishness has created a hole that can never be healed.
Ms. Niwunhella’s family paid tribute by saying, “We remember Nirodha as a beloved daughter, family member, and friend to many.”We shall always remember Nirodha with love, peace, and thanks.Her kindness and warmth affected many lives, and her memory will always inspire us.Even though her life was cut short, the love she gave us will always be with us. “Rest in peace, angel.”
“Thisara Weragalage planned his attack by going to the area several times before it happened and buying the murder weapon,” said Emma Davies of the Crown Prosecution Service.His planning was a big part of this terrible murder.
The Crown Prosecution Service’s overwhelming evidence showed his purpose and led to a guilty plea.The Crown Prosecution Service is working with the police to develop solid cases against people who commit violence against women and girls. Our prosecutors are also making sure that more victims of these horrible and terrible crimes get the justice they deserve.We are still thinking of Nirodha’s family and friends, who have lost someone very important to them.
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