An 18-year-old who was killed after he was found hiding at his secret girlfriend's home died from a stab wound to the heart, a jury heard.

Risaan Udayakumar, from Wembley, was allegedly found crouching in the garage of his girlfriend’s home in The Avenue, Watford, by her brother, then 16, on the evening of July 10, 2018.

The brother, now 17, who cannot be named for legal reasons, denies murdering Risaan.

At the time of Risaan’s death, their parents were away on holiday and the teenagers were under strict instructions to not have anyone round.

The jury at St Albans Crown Court were told the parents had “strict views” about relationships and their 19-year-old daughter, a university student, had not told her family about her relationship with Risaan, who was also on a degree course.

Instead he was introduced as a “friend”, although they had been in a secret relationship for around four months.

The court were told that just three days before Risaan died, a group of friends, including Risaan, had gone to the home in Watford to watch football on the television, and Risaan met the accused, even fist pumping him in a friendly gesture.

Three days later, on July 10, Risaan met his girlfriend at Watford Junction and they walked to the girl’s home.

Watford Observer:

A cordon in place in The Avenue on July 11

Prosecutor Michael Speak said for security reasons, doors inside the home were lockable and the girl had her own bedroom and bathroom.

When the girl’s uncle dropped by, Risaan hid in the garage, but when the uncle left, the pair went up to the bedroom.

The jury was then told the daughter began to feel worried about her brother finding Risaan when they heard knocking on a door in the house. Risaan went to hide in the garage again.

The prosecutor told the jury: “As soon as she saw her brother it was clear to her that he was very angry and he pushed her out of the way. He was clearly looking for someone, so he must have suspected she must have someone in the room.”

The jury was told he shouted “where is he? where is he?” and “who is with you?”

Mr Speak went on: “Having searched the bedroom and bathroom and having failed to find Risaan, the defendant went into the garage and there he found Risaan, who was down in a corner at the front of the garage. He was sitting down in a corner by the front door.”

Watford Observer:

The court was told the sister had followed her brother into the garage and then saw him set about her boyfriend by “hitting” him as he remained crouched on the floor.

The jury was told the victim offered no resistance and only raised his arms to shield his face.

The prosecutor said the girl had no idea that in fact her brother had armed himself with a knife.

Mr Speak said when the sister tried to get between the two teenagers, she realised blood was coming from Risaan’s mouth, there was blood in his shirt and a pool of blood was forming on the ground.

It was only then that she realised he had been stabbed and saw a knife in the hand of her brother.

A passer-by in the street that evening had heard screaming coming from inside the house and called 999.

He went into the property and found Risaan in the garage with the girl, who told him he was her boyfriend.

Mr Speak said that while there, the man heard the girl ask her brother “Why did you do this? You have a girlfriend” to which he replied he was “sorry.”

Watford Observer:

Police attended the scene and the brother was arrested and taken into custody.

Mr Udayakumar was rushed to Watford General Hospital, but nothing could be done to save him and he was pronounced dead at 10.41pm that day.

Consultant forensic pathologist Charlotte Randall told the jury today she had been shown of photograph of a blood-stained knife with a 18cm blade that is believed to be the murder weapon.

She said she examined the body of Risaan, who was 5 feet 10 and weighed 10 and a half stone, and found that: "Death was due to a stab wound to left side of the chest. It passed through skin, fat and muscle before entering the chest cavity."

She said a fragment of bone was chipped on the third rib before the sack around the heart was pierced, causing rapid and significant blood loss.

The pathologist said Risaan suffered two other stab wounds - one to the back and one to the left hand. She said neither would have been life-threatening.

The trial continues.