Slippery Debate

If capital punishment were a deterrent to crime...Texas should be crime free by now?

In a rare gesture of compassion, Texas shows mercy to someone who was just the 19 year old get away driver in a murder incident. The death penalty is required in Texas if there's involvement in a crime where murder has taken place without actually killing anyone yourself !

The debate inevitably invokes old testament references by Christians , which is barbaric since the same passages may describe the treatment of slaves.
Isn't the command, ' thou shalt not kill ' simple enough to need no further interpretations?
Of course religion should have nothing to do with the debate.