Bristol, and lots of other places, has litter wardens ('Environmental Enforcement Officers') wearing body cameras and, as far as I know, they only issue a fixed-penalty notice when they have the evidential footage which would be used in the Mags Court if the miscreant doesn't pay up. They can get you for dropping litter on the street or from a car, including chewing gum and cigarette butts; graffiti; painting or damaging a tree or road sign; flyposting; flytipping; nuisance parking; not putting your domestic or commercial waste out properly; breach of a Community Protection Notice; breach of Public Space Protection Orders, such as not clearing up your dogs' mess, not keeping your dog under control, taking a dog into an excluded area, such as an enclosed children's play area, drinking in a no-drinking area.
The blokes who nabbed me and my colleague made it clear they had footage, and that it would be deleted if the penalty was paid (£100, reduced to £70 if paid within 10 days, but now £150 & £75).