I've only ever had correspondence with the police once, personally, but found them to be really understanding, patient, helpful and have no complaints about the way they treated me. Another time a group of friends and I were going to an under 18s gig and we were standing outside our school with a few plastic bags filled with glowsticks and the like, the police came over to us and searched the bags 'cause they thought we had booze and were pleasantly surprised to discover we didn't, they said it made a nice change.