Deuteronomy 13:9 You must certainly put them to death. Your hand must be the first in putting them to death, and then the hands of all the people.
Many take things out of context and use religious writings to justify murder or other crimes; this is not the case with God’s Word!
God does not say we can go kill people just because they have done things wrong – there must be full and proper judicial process first of all.
If you take it on your own hands to carry out what you see as justice, then you are alone in doing so; always make full and proper use of all laws.