There's nothing wrong with getting to know both of them, that's the whole purpose of dating. Until two of you discuss having an exclusive relationship, then I say you are free to do what you want.

And on another note, don't "wait" around for the cop to find time for you, if he thinks YOU'LL be there when HE'S ready, then days, weeks, and months will fly by. I'm speaking from experience here, I did that for almost a year and finally came to my senses several months ago. Make him come after you, don't sit and wait for him.