Sure... try telling that to Bernie Goetz. I expect he'd tell you about how his year in prison and the $43 million civil verdict against him when you were done.
The law allows deadly force in defense against an immediate threat of great bodily harm or death. It doesn't allow it simply to detain your attackers on the floor when there's a bunch of other people around who could help you.
Your naïveté is ingratiating..