A teenager accused of stabbing a young father to death on a Stevenage doorstep told a jury today that he "regretted it so much".

The 17-year-old, who cannot be named for legal reasons, said he panicked when he saw his 15-year-old co-defendant being held in a headlock by Christopher Hewett.

Luton Crown Court heard 31-year-old Chris Hewett was attacked with a baseball bat by the younger boy outside his sister Robyn’s home in Meadow Way, Bedwell just after 9pm on the night of Friday, February 12 this year.

As he grappled with the 15-year-old, the 17-year-old is alleged to have come at him from behind and stabbed him. He suffered a large wound to his side and died in the arms of his cousin, Terry Wales.

In the witness box, the older boy said: “Chris had his arm around his (the 15 year old’s) neck. I could see him gasping for air. That is when I panicked. It was an instant reaction and I regretted it.”

He admitting pulling out his knife, but said it was to get the older men to stop fighting with the younger boy.

The youth went on: “I ran over and punched Chris. Terry hit me a couple of times. I was trying to get Chris off - that’s when I think I stabbed Chris. I think I stabbed him two to three times. It was just to get him (the younger boy) out of the headlock. I didn’t mean to hurt him."

His barrister Lewis Power QC asked: “Did you mean to kill him?” He replied: ”I panicked. I regret it so much.”

The 17-year-old told the jury he had been smoking cannabis every day in February this year. On the day of the killing he had two or three spliffs and two or thee cups of vodka. “I was not completely drunk. Out of 10, I was on five,” he said.

He said he carried the knife because he had been receiving threats on Snapchat from youths in another part of Stevenage.

Earlier, the court heard Chris Hewett and Terry Wales, who was visiting Stevenage, were making their way to Chris’ sister’s house when they passed a group of youths.

Prosecutor Paul Cavin QC said words were exchanged, with one accusing the victim of sending his mother “dodgy messages".

Mr Cavin said Chris Hewett replied that he did not known what they were talking about and walked on with his cousin.

“As they approached the front door in Meadow Way, the group was behind them.”

He said the 15-year-old was holding a baseball bat and delivered a blow to Terry Wales’ elbow. Christopher Hewett received a blow from the bat and was grappling with the 15-year-old, when the 17-year-old is alleged to have come from behind and made a number of stabbing motions.

The 17-year-old is later to have allegedly told a girl: “I have just shanked (stabbed) someone.”

The youths ran off and when Robyn Hewett opened her door she saw her brother being held up by Terry Wales.

Mr Cavin described the house as a “scene of considerable horror” with Christopher Hewett lying on the floor covered in blood. He had collapsed and was immediately gasping for breath.

The prosecutor said: “There was a large wound to his friend’s side which Mr Wales tried to compress. It was clear to him that Mr Hewett was struggling for breath and very shortly it was his view he died in his arms.”

An ambulance crew was called and he was taken to the Lister Hospital in Stevenage, where he was pronounced dead at 10.18pm.

The youths - who cannot be named for legal reasons - deny murder. A third defendant Ryan Lee, 19, of Wildwood Lane, Stevenage denies assisting offenders. It is alleged he arranged for them to travel to Wakefield in West Yorkshire after the killing.

They were arrested in a car on Sunday, February 14 in Cambridgeshire.

The trial continues.