A teenager who stabbed his sister's secret boyfriend to death has been found guilty of manslaughter.

The 17-year-old, who cannot be named for legal reasons, was convicted today for the death of Risaan Udayakumar, who died after he was stabbed at a house in The Avenue, Watford, on July 10.

The killer, 16, at the time, arrived at his home, and suspecting his sister had someone with her, eventually found Risaan hiding in their garage.

He had armed himself with a knife and began stabbing the 18-year-old.

Risaan, from Wembley, was rushed to Watford General Hospital but died later that evening, at 10.41pm. Tests confirmed he was killed from a stab wound to the chest.

Watford Observer:

A cordon in The Avenue on July 11

Risaan, a student, had been in a relationship with his girlfriend for around four months, but the girl’s family believed them to just be friends.

The girl’s parents were away and she and her brother were under “strict instructions” to not have anyone round the house.

On July 7, Risaan, a former pupil at QE Barnet Grammar School, and a number of other friends were at the house in The Avenue to watch a game of football, and Risaan and the brother even met and spoke to each other.

Three days later, the 19-year-old girl met her boyfriend at Watford Junction and they walked back to The Avenue.

That evening, she hid Risaan in the garage when an uncle called by the house to check everything was okay. When he left, the girl and Risaan were together in her bedroom and the internal doors had been locked.

Watford Observer:

Proescutor Michael Speak said the couple had been in the bedroom for about half an hour when her brother returned home unexpectedly.

He was “angry” and shouted “where is he, who is with you” before searching the house.

He found Risaan crouching in the garage, and having armed himself with a knife began stabbing him, as his sister watched on in horror, before she tried to pull her brother off her boyfriend.

A passer-by heard screaming and called 999 and the 16-year-old was arrested.

A jury found the defendant guilty of manslaughter through loss of self-control. He has been remanded in custody for sentencing, which is set to take place next month.

Watford Observer:

Risaan’s father Kandasamy Udayakumar paid tribute to his son and described his sadness at not being able to see him grow up.

He said: "Risaan wanted to make a difference in life and his dream was to build a Formula 1 track. This is a dream he will never fulfill and a dream that we will never be able to see.

"The pain that we feel as a family has also been been felt by the community as he could have made great things and would have made his country proud.

Watford Observer:

Risaan Udayakumar

"We have been robbed of so many dreams and so many memories that we should have made as a family. We should have been able to see him grow up. We should have been able to see him graduate from university and possibly get married and have children.

"Not a moment goes past when we don't think of Risaan.

"Risaan was very family orientated and did not believe in violence."