Read some of the stories of the women he helped here. The recurring theme is that these late term abortions happened because these women wanted so much to have a baby that they would not terminate until they were absolutely sure - after multiple tests - that the fetus had a condition incompatible with becoming a baby that could live and grow. And because they waited, they had to go to Kansas, since there was no provision in their home states for this procedure. And in Kansas, they encountered a doctor universally described as both caring and competent and an angry mob they had to pass through to get to him. Now only the angry mob is left - Dr. Tiller has been gunned down in his church by a long time anti-abortion activist.
The anti-abortion movement encourages this violence every time it refers to a fertilized ovum as a human being, every time it calls doctors "murderers", every time it uses the Orwellian double speak technique of calling their goal of enslaving women "the prolife movement." His blood is on their hands. And I wouldn't be surprised if this death results in a lot of abortions that wouldn't have happened otherwise, as women are advised to not wait for those confirming results, but terminate while they can still do so safely at home. "You'll get another chance to get pregnant if you terminate now," they'll be advised, "but you may not get a chance to terminate if you wait."