The Bible addresses in much detail the differences between cold-blooded murder, manslaughter, revenge killing, capital punishment, killing in self-defense, killing as part of your duties (e.g. soldiers killing in combat), etc.
Murder is punishable by death. Manslaughter is not. Revenge killing is wrong. Capital punishment is not. Killing in self-defense is justified. Soldiers killing combatants is justifiable, too (it's an expanded form of self-defense, because soldiers are defending themselves, their platoons, their country. It is not OK for soldiers to abuse their positions for their own selfish gain, though. The Bible forbids them to rape, pillage, and deliberately kill innocents).
I wish I could supply you with verses, but can't off the top of my head. If you do research it, you will find ample verses in the Bible that support what I've said.
The Bible does not specifically use the word abortion that I'm aware of, but does address the unborn. A child in the womb is regarded as a miracle, a wonder, and as a person that God already knows and loves.
I don't see how anyone who reads the Bible can honestly believe that God would condone killing unborn children. Everything that God says about how we should treat one another (do unto others as you would have done unto you, love thy neighbor as thyself, etc.) tells me that God would view abortion as a terrible, terrible sin.