Louis Boduka Mudianga’s father brought him to Britain aged three in search for a better life than that in war-torn Congo.

A decade and a half later, on January 21, he was killed on the street in Edmonton, North London, by another teenager who stabbed him through the heart with a three-inch flick knife.

“Maybe we would have been better staying in Africa, maybe not, but maybe my son would still be alive,” Frank Mudianga, a computer engineer, told The Times. “My son never carried a knife. He was into dancing, not fighting, and was a good kid.”

The Old Bailey trial of his attacker was told that there was a history of gang warfare in the area. Louis, 18, may have been on the periphery of it. To Mr Mudianga’s bitter disappointment, Kevin Lewis, 18, his son’s killer, was jailed for five years last week for manslaughter. Mr Mudianga said: “It should have been a long sentence, to send a message to other teenagers not to carry a knife. But he will be out in a few years – my son will never come back.” He said that his other children were struggling to understand the loss of their brother. “His sister had to see her older brother lying in a coffin. This is not good.”

Mr Mudianga’s own health has suffered since the killing. “I see my GP to receive medication for anxiety and depression,” he said. “My younger daughter needs help from an educational psychologist. The whole family and all of Louis’s friends are deeply distressed.

“Every time I see a young man in the street who looks a bit like Louis, I think it is Louis. It is like a bad dream.”

Times Recommends

• Milk: do we need a dairy godmother?
• DIY: the women doing it for themselves
• First double portrait of Princes unveiled