Two years ago an older couple moved in across street. We have lived here 5 yrs. Animal control was called to our home on 3 separate occasions saying complaints of big loose dog. Each time our dog was in the gated yard. Next accused us of a hit and run when our car was not even involved. Then she began walking the neighborhhood at all hours of the night. Also is telling people we are drug dealers. Recently learned she has told the cops the same thing and that she is writing down all the license plates of people who come over. We are not the only neighbors she bothers, she calls cops for anything true or not. Tells people her family works for city PD, used to be guard so she tells them always has a bat and knife. I am tired of looking the other way. Please help

They are digging their own graves by calling the cops for every little thing, and the cops are no dummies - they will soon ignore them if they haven't already.
I would suggest that you print out about 10 notes for your neighbors and knock on their doors and hand them to them, with an invitation to write down their problems with the couple, and then arrange a meeting at your house to deal with it. Safety in numbers. Call yourselves the Elm St Watch or something, keep notes, and have a spokesperson for the police. But don't call the police about what the couple does; only be available as a group if a concrete situation arises. You don't need to be a lot of work for the police either, and they will appreciate it.