Apparently I need to explain the definition of murder for you so to better represent the facts.
Murder is the unlawful killing, with malice aforethought, of another human,
Since abortion is not unlawful, it is not murder, therefor your use of the word murder makes your argument faulty.
Pointing out a flaw in your argument is not a defense of abortion.
So is it murder when a man lawfully kills his wife under sharia law?
Was it murder when slave owners killed their slaves?
When you have laws that permit human rights violations, even though the law determines at that time you have not committed a crime, you have still committed a crime against humanity. Germany understands this, now....laws that legalize murder are bad law, and when people establish them, it's just a matter of time before the society crumbles and the people who established the bad laws are exposed as fascists and murderers.
The doctors who killed in the name of improving the race, though they were perfectly within the boundaries of the current law in doing so, were ultimately put on trial for crimes against humanity, and some of them were hanged. I wouldn't hold too dearly to the concept that "if it's legal we don't have to worry about it, it's okay". Ultimately, the world will judge the people who establish such laws and act accordingly...and they will be held accountable...as will the people who were willing to look the other way.