What snake is this

I found this in my back yard today.  At first I was going to just leave it take off, but then I noticed some strange behavior.  It is about 8" (inches) long, it has markings unlike any garden snake I have seen around here before, and it stikes.  So I now have it in a bucket, if it is a friendly snake, meaning it can bite but not poisonus I want to set him free. But if he is one of two other varieties of vemonous snakes we have around here, I am afraid he is about to meet an untimely end.  Please let me know if you know what this guy is.

You will notice the tail, I think I might have inadvertantly stepped on him.