As to capital punishment, there are those who believe that the taking of life, under any circumstance, is wrong; just as there are those who believe that under certain circumstances, the taking of life is permitted according to the Bible.

In addressing the subject as to whether, or not, government has the right to administer capital punishment, we must recognize that it is God who has instituted governmental authority within society.  It is also God who has given government the authority to punish wrongdoers; even to the point of death.¹

When Jesus was brought before the Roman governor Pontius Pilate just prior to His crucifixion, Pilate threatened Him with the words, "Do you not know that I have power to crucify You, and power to release You?"  In response,  Jesus did not say that he did not have this power, but, rather, responded by saying that whatever power Pilate possessed over Him (as the governing authority in Judea) was ultimately from God.²

Bible References:

¹ (Romans 13:1-5)

² (John 19:10-11)