In his new biography on Dietrich Bonhoeffer, author Eric Metaxas quotes Bonhoeffer's thought.
“Destruction of the embryo in the mother’s womb is a violation of the right to live which God has bestowed upon this nascent life. To raise the question whether we are here concerned already with a human being or not is merely to confuse the issue. The simple fact is that God certainly intended to create a human being and that this nascent human being has been deliberately deprived of his life. And that is nothing but murder.”
Bonhoeffer was crystal clear on the morality of abortion. It is murder.