Just asking this as yesterday evening I stumbled across this old episode of the programme from April 1991 titled 'Hot Dog Wars' on YouTube.
In that particular episode, Roger Cook exposed 'illegal' hot dog/fast food vendors who were not only involved in organised criminal gangs but were also sabotaging and attacking fully 'legit' hot dog/fast food vendors, including the mention of one particular high-profile incident in Leicester the previous year (1990) that involved a murder. All very heavy (and indeed cringeworthy) stuff that I was totally unaware of at the time (nearly 14 years old) but would totally creep me out if there were regular reports of such things happening today, let alone all the usual knife crime stuff.
That Roger Cook was surely a brave man and must have really had a thick skin in order to successfully confront and help to bring to justice a lot of the psycho sh1tebags of the UK's criminal underworld. A true genius and a hero!