THE detective leading the hunt for Steven Grisales' killers has hit out at the “horrifying” knife crime culture in London.

Detective Inspector Richard Beadle is heading the investigation into the murder of 21-year-old Mr Grisales, who was fatally stabbed in College Close, Edmonton, a week ago today.

Speaking at the scene of the stabbing, he said: “This was totally, totally unnecessary and another sad indictment of how easy and quickly someone can lose their life simply by someone carrying a knife.

“It is really upsetting for everyone that someone's actions can result in a young man losing his life.

“It is horrifying that so many people are carrying knives in London and are prepared to use them.”

Mr Grisales' parents today made an emotional appeal for Edmonton residents who witnessed the attack to come forward and help police catch their sons' killers.

He was walking along College Close to Silver Street station at around 7pm when at least three black youths started throwing conkers at him.

When Mr Grisales remonstrated with them, one is thought to have pulled out a knife and stabbed him.

DI Beadle said: “It appears there was some sort of unnecessary interaction and an argument in the street.

“It deteriorated quite quickly, quite suddenly, and resulted in young Steven being attacked and stabbed.

“Steven was simply walking to get his train home and got involved in an incident not by his own making.

“There were quite a lot of people who would have seen that, quite a lot of people who know what happened.

“We need to find out who did what, what Steven's part was in this, and most importantly who is responsible for the murder.”

He said several witnesses have already come forward, but urged anyone who has not told police what they know to call 0208 721 4961, or contact Crimestoppers anonymously on on 0800 555 111.

A 15-year-old boy from Enfield was charged last night with murder, and is due to appear at the Old Bailey tomorrow.

Four teenagers, two girls aged 16 and 15, a 19-year-old man and a 15-year-old boy, have been questioned in connection with the killing and released on police bail.