Earlier quoted context omitted.
That's not true in the UK. Police can use reasonable grounds to search and they don't need a dog to alert to give them those reasonable grounds. The dogs, if used, in the UK probably are sniffing actual drugs. Here's some legal information: https://www.citizensadvice.org.uk/scotland/law-and-courts/le...
It looks like it's true. > You can also be searched if the police have reasonable grounds to suspect you have: > illegal drugs Use a dog. Pretend it's reasonable grounds. > In all situations, you can’t be searched just because of how you look or who you are, as this is discrimination. Yes it is and that's how you use a dog to discriminate and maintain the legal fiction.
Furthermore, reasonable grounds is a low bar. From the code of conduct in the linked document (Scots law, but the whole UK is similar)[4]:
> Reasonable suspicion may also exist without specific information or intelligence and on the basis of the behaviour of a person. For example, if a constable encounters someone on the street who is obviously trying to hide something, the constable may (depending on the other surrounding circumstances) base such suspicion on the fact that this kind of behaviour is often linked to stolen or prohibited articles being carried
A police dog is frankly overkill for establishing reasonable grounds.
[1] https://hansard.parliament.uk/commons/2016-11-14/debates/D85...
[2] https://en.wikipedia.org/wiki/Police_dog#United_Kingdom
[3] https://www.washingtonpost.com/news/wonk/wp/2015/11/20/the-s...