Dr. George R. Tiller had many critics, but arguably the one with the highest profile was Bill O’Reilly, the Fox News Channel host. Mr. O’Reilly, a vocal opponent of abortion, often called him “Tiller the baby killer” for performing late-term abortions and said repeatedly that he had “blood on his hands.”

Within hours of the shooting that left Dr. Tiller dead on Sunday, Mr. O’Reilly found himself under attack from liberal journalists and bloggers who accused him of inciting violence. By early Monday, some Web sites were asking, as a newsletter from the Air America radio network did, “Is Bill O’Reilly to Blame for Murder Of Kansas Doctor?”

Mr. O’Reilly responded to the critics on his program on Monday night, saying that “clear-thinking Americans should condemn” the killing. He defended his remarks about Dr. Tiller, declaring that “every single thing we said about Tiller was true, and my analysis was based on those facts.”

Finger-pointing is nothing new, but the nature of the accusations thrown at Mr. O’Reilly show the swiftness and vociferousness with which the blame game is now played.