Nathaniel Armstrong, 29, was killed just 11 Mr Beresford interrupted a debate on stabbings to give an impassioned plea on knife crime.
The 38-year-old said that he was from the community hit by London’s knife crime epidemic and called for young men to be given opportunities.
A murder investigation was launched after Nathaniel was fatally knifed at the junction of Gowan Avenue and Munster Road in Fulham in the early hours of Saturday.
Neighbours said they heard an argument unfold at about 12.30am before cops and paramedics arrived at the scene – the same street where Crimewatch host Jill Dando was fatally shot in 1999.
The 6ft 7in victim has been described as a “good guy” and “big friendly giant” who lived on a street roughly 100 metres away.
Alex, 38, was told of the murder yesterday afternoon. A source told the Sun: “He’s in a state of shock.
“It’s so tragic, especially when you think he spoke out about the knife crime problem so recently.”
Weatherman Alex called across ITV’s breakfast show studio to interrupt a panel debating whether there should be more jails.
He blasted: “Prison doesn’t work though. It does not work. I’ve grown up in some of these communities you guys are talking about. Some of these boys don’t fear prison.
“If you don’t change the environment you won’t change anything and that’s the key thing.”
Met Police said yesterday that formal identification was yet to take place and a post-mortem examination will take place in due course.
DCI Glen Lloyd is leading the investigation. He said: “This murder investigation continues apace.
“Police work at the crime scene is ongoing. Active enquiries are in hand.
“We are appealing for information from those who were out and about in the area at the time of the attack and saw anything of note.
“My team is particularly keen to trace a light skinned black male, approximately 6ft tall who was seen near the scene at the time of the incident.
“Did you see him? Do you know who he is? Anyone with information on his identity or whereabouts is urged to contact police.”