I am a fan of GOOD POLICE, with that said they are far and few between. 1st) I always carry a copy of my states motor assisted bicycle code.
2nd) when ever I can I record interaction with police, video and audio (this is legal in all 50 states, officers have no expectation of privacy in a public domain while on duty). this way if they misbehave you have proof, this will be needed if you file a complaint, enough compliants and he'll lose his job, enough of them from one person and it is basis for a harassment suit. If you have a fenced yard keep the gate closed ( they must have an invitation or a warrant to enter) an open gate is considered an invitation( legally speaking). Remember, always try to be patient with cops, most of them are on the job because they couldnt make it in the military and didnt have the education to get a better paying job in the public sector.
As for the neighbor some people may be apt to return the favor calling the cops and telling them "the person @ (insert address) just tried to sell me drugs" They will go and speak to them. It will end in one of a few different ways, Officer ask them "may I come in and look? " 1)They tell him "NO" this makes them look as if they have something to hide. The cops will then keep a close watch on their daily lives looking for the chance to pull em over and look around. 2) The neighbor is stupid enough to say "sure" upon which the house will be searched and turned inside out wether anything is found or not. But I know some unsavory types of people,lol. Cops are like any other tool, there to be used.