david gunn is shot to death in pensacola, florida. 1994, two clinic workers are murdered in brooklinehusetts. 1998, dr. barnett sluffian is gunned down by a sniper as he stands in his own kitchen in buffalo, new york. in addition to three other murders, the national abortion federation reports that more than 200 american clinics have been subjected to bombs and arson since 1977. >> those are acts of domestic terrorism, which are intend ed o intimidate. so if i kill one doctor, maybe i'll intimidate 100 doctors. >> my business is legal. their business of anarchy is illegal. >> george tiller was one doctor who could not be intimidated. he was one of just three physicians in the united states who specialized in abortions done in the second and third trimesters of pregnancy. >> he was not shy about publicizing what he did, and he certainly never apologized for what he did. so it was a love/hate thing. very few people had no feelings regarding dr. tiller. >> the first real flash of violence strikes in 1986, when a bomb is set off at the entrance to his clinic. >> we have had a major $100,0