About a month ago I purchased Ketamine from someone in San Francisco who recently was arrested for possession with intent to distribute. It has come to my attention that I may need to be worried. I paid him with a wire transfer, which would link us to one another. I no longer possess anything, and don't regularly participate in this kind of activity; but he was evidently a large supplier to several dealers in the area. I need to know whether or not the police can detain me even though I possess nothing. Please advise.