I am known everywhere as a criminal, yet I have never done anything illegal. I always have an inside angle on you, and there are two of me for every one of you. What am I?
I am... the crook of an elbow! The crook is called a crook (obviously), and as your arms are on the side of your body, the insides of your elbows most nearly always have an inside angle on you; it's not psychological at all! And for every arm is an elbow, so two elbows means two crooks of an elbow per person.