Murder objectively violates the rights of others. Same with stealing. Same with abiding by deuteronomy chapter 13. That's why we don't allow these things. My standard is respect for the basic human rights laid out in the constitution. If you want a theocracy, might I suggest Uganda or Pakistan or Iran? Basically just get in a plane and find a horrible hell hole. Chances are, it'll turn out to be exactly what you're looking for. Somehow though, I doubt you'll be happy when you get it.
Thankfully, religion is on the decline. Especially your religion. Senseless murder of innocent people just isn't as popular as it used to be. Tough for you. Just take a look at the next generation. They're already digging a grave to unceremoniously dump your dream of a theocracy into.
Our theocracy is the kingdom of heaven...Jesus Christ is our King, it is just our hard lot that while we await our Master we have to dwell among His enemies.