They have to be very careful with this story. On the one hand, they want to use it to smear those hated “pro-lifers”. On the other hand, they need to avoid having it lead to the question of “What exactly was this guy doing that made him such a target?” That would lead to people actually knowing what their “choice” thing is all about and they most emphatically don’t want that.
"How horrible! He associated with people who support the right to life and try to save babies!" That doesn't go over very well if you think about it, does it?
Or, "He killed George Tiller because he had a violent hatred of abortionists--especially late term abortionists--especially the most notorious abortionist in America, the man who made Kansas infamous, who bought the election of a district attorney who favored him, and who bribed the governor in his successful efforts to buy off prosecution for various crimes he committed in violation of Kansas law."