First of all, God isn't a murder. Why not? God owns everything. So, even if He takes life away, He was the One Who gave it in the first place. It is His by right, to do with as He pleases.
Murder is purposely killing a person. Whether or not you own that person is not in the definition - the only important thing is whether or not the murder was "lawful".
God can't be left out of any of the picture. The whole operation of people dying is something that happens in the process of God maintaining every little thing in the universe. His maintenance of everything includes giving us death when we ask for it. This isn't the same as simple murder. Things are completely different from the God-standpoint than the man-standpoint.
If God exists and is omnipotent, or even only omniscient, it will obey no human laws and so if this God kills a person in a way that is not allowed by the laws of a particular nation, it does so unlawfully. It doesn't matter that you think this God's law should have primacy.
God's law is to not murder. The laws of nations come about because people are basing their laws on what God has set in place... although often people mess God's perfect laws up when they don't consult Him first.
Given the above (God exists, God is at least omniscient) then if a person's death results from this God's actions in a way considered unlawful by a given nation, then that God has committed a murder in that nation.
Quite the contrary. God is maintaining life. It is mankind who has brought death upon himself. However, since God controls everything, it is His doing that exercises mans' request for death, be that request by voice or by action.
Interestingly this means that God cannot commit murder in countries that have religious laws since I'm fairly certain they would by definition exempt their God from any crime.
Here is where you fail in your thinking. God has prepared a day of resurrection for all people, where He will bring us all back to life. At that time, he will separate the righteous from the unrighteous. The righteous are those who have believed in God for the salvation offered through His Son, Jesus. The unrighteous are those who have not believed God, or have sought salvation by some other method than Jesus even though they might have believed God exists.
You have a chance, now, by reading this writing. Come to faith in Jesus God before you lock yourself into unbelief by dying without faith. after all, once you are dead, you can't change anything about your situation.