Dr. George Tiller was shot and killed yesterday, May 31, in the vestibule of his church in Wichita, Kansas. Police reportedly arrested a former right-wing militia member for the assassination. The suspect apparently had run-ins with law enforcement in the 1990s, including for possession of bomb-making materials, and seemed obsessed with the abortion issue, according to his ex-wife. But is he the only one responsible?

This isn't the first act of violence against Dr. Tiller or other women's health services providers, and women's groups immediately denounced the killing. In a press statement, National Organization for Women President Kim Gandy described the slaying of Dr. Tiller as part of a long pattern of 'domestic terrorism' that deserves a special investigation by federal law enforcement authorities.

'We call on the new Attorney General Eric Holder and head of Homeland Security Janet Napolitano to treat these murders in the same way they would treat politically-motivated domestic terrorism of any other kind and put the full resources of their two departments behind that effort,' Gandy said.

As part of its coverage of the slaying of Dr. Tiller, the Associated Press produced a list of 10 bombings and shootings over just the past 15 years where abortion providers, staff and clinics were targeted.

Any federal investigation needs to scrutinize also those individuals and groups who have encouraged such violence. For example, militant anti-abortion group Operation Rescue founder Randall Terry has done his part to encourage violent actions against clinics and doctors who provide abortions. One Kansas commentator got it right when he linked Terry's decades-long efforts to brand Tiller as a murder who deserved death to Tiller's assassination on May 31.

While Operation Rescue officially denounced the shooting after the fact, Terry apparently could not restrain his glee at the news of Tiller's assassination. 'George Tiller was a mass murderer and we cannot stop saying that,' Terry said. 'He was an evil man – his hands were covered with blood.'

In comments posted on website after website, anti-abortion militants justified the assassination of Dr. Tiller. Several even compared the killing to the shooting of a 'Nazi guard' at a concentration camp.

Then there is Mark S. Geitzen, of the Kansas Coalition for Life, another group that for years harassed Dr. Tiller and the workers and patients at his clinic and labeled him a 'killer.'

The depth of the violent language used and circulated by groups like Geitzen's is exemplified in an e-mail to his supporters last October regarding the presidential campaign. Geitzen wrote of Barack Obama's support for a woman's right to choose: 'This election is a clear choice between good and evil.' He added that an Obama presidency would bring a 'blatant evil' on the country and that his candidacy should be opposed.

Geitzen went on to say that someone voting for Obama is like 'someone aiding a person who is planning to do a school shooting… only much worse!' A comparison to school shootings is more than symbolic; they usually don't end with an arrest by police and a subsequent court trial.

The e-mail included two Bible verses from the book of Ezekiel (3:18-19). 'If I say to the wicked man, You shall surely die; and you do not warn him or speak out to dissuade him from his wicked conduct so that he may live: that wicked man shall die for his sin, but I will hold you responsible for his death.

If, on the other hand, you have warned the wicked man, yet he has not turned away from his evil nor from his wicked conduct, then he shall die for his sin, but you shall save your life.' In any context, the verses seem to justify the death of a person like Dr. Tiller whom Geitzen and Terry labeled as a murder and whom God, through the hand of someone on earth, would punish.

Back in October, I asked Geitzen by e-mail if he thought that sending out these Bible verses might encourage violence against candidate Obama for his beliefs about a woman's right to choose. In response, Geitzen insisted that anyone reading the book of Ezekiel would not take the words literally, but, in fact, would know that Ezekiel referred to a 'spiritual death.' Geitzen included none of this explanation in the original mass e-mail.

Contradictorily, however, Geitzen and many supporters and ideologues of the militant anti-abortion movement base their views on literal interpretations of the Bible. Indeed, they typically accuse other religious people who refuse to take the Bible literally of being hell-bound false prophets. They only make such fine distinctions about the meanings of 'killer,' 'death,' 'murder,' 'evil,' when pressed, or after terrible incidents that make their movement appear violent.

Obviously, the man who allegedly killed Dr. Tiller made no such a distinction.

Of course, now Geitzen and his group are pleading for 'understanding.' In an e-mail circulated May 31 after news of the assassination of Dr. Tiller spread, Geitzen sent a press release by e-mail asking 'all reporters and commentators to make a clear distinction between lawless thugs who act on their own accord, and the good proLife people who obey the law.'

Perhaps not accidentally, Geitzen's electronic press release also bore Dr. Tiller's mugshot. Tiller had been arrested in 2006 by Kansas Attorney General Phill Kline, an outspoken opponent of abortion. A judge threw out that case. Several months later, however, Kline brought charges again, and Tiller was acquitted of all charges just this past March. Did Geitzen intend, even after Tiller's murder, to send the message that he thought Tiller to be a criminal who deserved such justice?

Even more disturbing is the possible suggestion that a lawful court couldn't punish Tiller, so God's justice was meted out by other means.

People of conscience, however, can make little distinction between the violent rhetoric that openly calls for God's judgment on people like Dr. Tiller (or President Obama) and the actions of the man who took Dr. Tiller's life. Indeed, the law provides for prosecuting individuals or groups that incite or encourage violent acts. The dimension should be carefully examined in the ensuing investigation.

Most importantly, this case should give us pause to reexamine our handling of the abortion issue as a country. President Obama's reasoned approach to the question is a good starting point. Let's tone down the rhetoric and speak to one another as members of a shared community, rather than us good people vs. them evildoers.

Most Americans, though uneasy with or disapproving of abortion, respect a woman's private medical and moral choices. Most also rightfully reject elevated rhetoric about who is a murderer and who is deserving of God's judgment, especially as determined by political organizations with religious affiliations.

A respect for the privacy of women and their health needs should be combined with our common concern for using scientifically- and medically-endorsed methods for reducing the number of unintended pregnancies.