A death sentence for abortion doctors?

Anger at revelation that anti-abortionist who killed medic may make so-called 'necessity defence'

Combatants in America's long-running abortion debate were plunged into fresh controversy yesterday after a judge in Kansas indicated that he would not rule out considering a voluntary manslaughter defence in the trial of Scott Roeder, who has already confessed to the killing of a leading abortion provider in Kansas last year.

Abortion rights activists were furious yesterday at a ruling that they said amounted to a "death sentence" for doctors who provide the procedure, and prosecutors were due last night to challenge the judge's decision in a pre-trial hearing in the case. They are seeking a first-degree murder conviction of Roeder, who does not deny killing George Tiller, who was one of only four doctors in the US to offer late-term abortions.

Indeed, prosecutors had felt assured that they had a fairly open-and-shut case with 250 potential witnesses ready to testify about the events on 31 May last year, the day of Dr Tiller's death near his clinic in Wichita, Kansas. Witnesses say Roeder rose from a pew at the Reformation Lutheran Church at the start of the Sunday morning service, walked to the foyer at the back where Tiller, an usher, was chatting to friends, drew out a gun, pressed it against the doctor's forehead and pulled the trigger, killing him instantly.

But the trial was thrown into turmoil on Friday, when Judge Warren Wilbert acquiesced to a defence request to allow the defendant to argue that the murder was a justified act because of his belief that in killing one man he was saving the lives of unborn babies. Sometimes dubbed a "necessity defence", a conviction for voluntary manslaughter which could be punishable by as little as five years – instead of life – in prison.

The decision has appalled supporters of abortion rights. It appeared even to have caught anti-abortion activists by surprise. A necessity defence has never before been allowed in trial involving the killing of an abortion doctor. Moreover, some people argued that it could mean open season on clinics and doctors if would-be killers think they might be punished with only a few years in prison.

"This judge has basically announced a death sentence for all of us who help women," said Dr Warren Hern of Boulder, Colorado, a friend of Dr Tiller who also performs late-term abortions. "That is the effect of the ruling." Voluntary manslaughter is defined in Kansas law as "an unreasonable but honest belief that circumstances existed that justified deadly force".

The controversy has already delayed the trial that was meant to begin with jury selection on Monday. It was postponed until today at the earliest.

While the judge has said for now that he will allow Roeder to build a case for a voluntary manslaughter conviction, he has still not made up his mind whether he will allow the jury to consider that alternative and will not until after the trial has started.

One legal observer told both sides in the fight not to overreact. Judge Wilbert is "just saying he's approaching it with an open mind", noted Tom Brejcha, a lawyer with the Thomas More Society, a public interest law firm that has argued both right-to-life and euthanasia cases in America. He will use "ordinary sound judgement before awaiting the presentation of the evidence".

Dr Hern bemoaned the ruling. "It is an act of incomprehensible stupidity on the part of the judge," he said. "But he is carrying out the will of the people of Kansas who are trying to get out of the 19th century."

The developing situation in the Wichita courthouse might encourage federal prosecutors to step in and file their own charges against Roeder for violating federal statutes that guarantee a woman's access to medical clinics. Most termination procedures are legal under the landmark 1973 Roe v Wade Supreme Court ruling.

The position of the judge has thrilled the extremist wing of the pro-life movement. "The trial is important to us," said Donald Spitz of the Army of God, a group that refers to Roeder as an "American hero" on its website. "Pro-lifers have been convicted unjustly for years in the court systems because they have not been allowed to state why they took their actions against abortion mills or against baby-killing abortionists."