Covering the police beat

Today at work, when pursuing some leads on possible crime stories, I was reminded of just how important it is as a journalist to be 100% cooperative with the police. If they ask you to hold off on a story due to a person not being formally charged, do it. If they ask for something to be kept off the record, do it. I know we all want to get the big scoop, but fewer things can be more crippling to the journalist than an alienated police department that won't provide them any information on stories.