I do not wish to take sides in the Political divide here, but I expect that Ben Bradshaw's leaflet said something like, "crime has dropped by 25% since Labour took control" suggesting a cause and effect that doesn't really exist.
This is a time honoured method of saying one thing but implying something different. I've spotted this a lot with Politicians.
Consider something like, "the rise and fall of the graduation rate at Cambridge University during the 1970s was exactly mirrored by the number of convicted sex offenders in New South Wales, Australia". No one with any sense could say that one thing influenced the other, but the Politician's trick is to find things that people think are connected then make those weasel word non-connections.