As far as I knew, my son had been sober for two years. But, I found a needle in his desk drawer yesterday. He swears it's leftover from the past, but that seems hard to believe. I told him I would call the cops if I ever found drugs in my house again. I don't want to be around that, and I have to consider the safety of my eight-year-old daughter too. Should I believe him and let it go? Should I insist on searching his room and his car? Or, should I call the cops and throw him out now?