Nigerian parents, John and Linda Burke-Monerville, are demanding justice for the murder of their three sons in London, United Kingdom.
The couple lost the latest to an attack in Barnet last month. David, 38, was stabbed to death in a fight.
David's brother, Trevor, had first lost his life in 1994 after being attacked by five men, before another of his siblings, Joseph, was killed in Hackney in 2013.
The family had previously sent Joseph and his twin Jonathan, the only surviving son, to boarding school in Nigeria to keep them away from crime.
According to the family, none of them have ever been in trouble with the police.
The parents spoke with UK's The Guardian according to a report by Daily Mail, saying the latest murder has been like 'a terrible dream' for them.
"I was a teacher and always taught my children the value of education. I don't understand why this keeps happening to us... Why can't we have peace? Why couldn't our children be allowed to grow up like other children?" Mrs Burke-Monerville said.
David had been campaigning for justice over the deaths of his brothers, whose killers have still not been found.
At the time of his death, David, a father of two boys, had just begun a new job, one of two positions he worked to take care of his family.
Three men have been charged with aggravated burglary over his death and the family hopes they will finally see one of their sons' killers brought to justice.