( CNN ) -- An anti-abortion activist charged with gunning down a Wichita , Kansas , doctor can not use the `` necessity defense '' at trial , a judge ruled Tuesday . Scott Roeder , 51 , is set to stand trial January 11 on one count of first-degree murder in the death of Dr. George Tiller , who was shot to death at his church May 31 . Tiller ran a women 's clinic in which he performed abortions . Tiller , 67 , was one of the few U.S. doctors who performed late-term abortions . He had already survived one attempt on his life before he was slain . Under a necessity defense , a defendant argues an action was justified because breaking the law was more advantageous to society than following it . Several anti-abortion activists facing criminal charges have attempted to use the defense but none has been successful . In an Associated Press interview last month , Roeder admitted killing Tiller and said he plans to argue at this trial that the shooting was justified . `` Because of the fact preborn children 's lives were in imminent danger , this was the action I chose , '' he said . `` ... I want to make sure that the focus is , of course , obviously on the preborn children and the necessity to defend them . '' Roeder 's comments prompted prosecutors to file a motion asking Sedgwick County Judge Warren Wilbert to bar Roeder 's attorneys from using the defense . Wilbert noted that the Kansas Supreme Court , in a previous case regarding blocking entrance to an abortion clinic , ruled the necessity defense can not be used when the harm the defendant claims to be avoiding through his or her actions is a constitutional and legal activity , and the defendant broke the law . That precedent , Wilbert said , required him to rule that the necessity defense is not a viable defense in Kansas or in the Roeder case . Defense attorney Mark Rudy pointed out to Wilbert that the defense team has not yet acknowledged what their tactic might be . Roeder , however , filed a 100-page motion on his own behalf , Sedgwick County District Attorney Nola Foulston said Tuesday , on the necessity defense , acknowledging it previously has been unsuccessful . Prosecutors also asked Wilbert to bar Roeder 's attorneys from claiming his alleged actions were justified because he used force in the defense of another -- the unborn . Wilbert said that would require further argument -- particularly an offering from defense attorneys regarding the evidence they plan to present in support of that premise at trial . `` I will leave the door open on the issues surrounding use of force in defense of another , '' the judge said , adding he does not mean it 's `` wide open . '' Under the law , such a defense can only be used if a defendant was preventing unlawful conduct . Foulston argued that Tiller posed no threat that would justify his shooting . `` Dr. Tiller was not an aggressor , '' she said . Roeder is also charged with two counts of aggravated assault for threatening two church members . Dressed in a coat and tie , he conferred with his attorneys and listened intently to the arguments on Tuesday . In a June interview with CNN 's Ted Rowlands , Roeder would not admit that he killed Tiller , but said that if he is convicted , `` the entire motive was the defense of the unborn . '' Roeder 's attorneys also argued Tuesday that the trial should be moved outside Wichita because extensive pretrial publicity in the case could have tainted the jury pool . Foulston , meanwhile , noted that Roeder , who has talked often to the media , brought some of that publicity on himself . Wilbert said 300 jury summonses have gone out in the case , and he was optimistic that some impartial jurors could be found . However , he said he would revisit the issue later if the court experienced difficulty in picking jurors . Rudy also asked that the judge prohibit prosecutors from excluding potential jurors because they have anti-abortion beliefs . The judge said he was confident that some individuals who are anti-abortion would still be able to make an impartial decision , but suggested the issue be examined on a juror-by-juror basis if the court recognizes a pattern of exclusion during jury selection . `` I ca n't make a pretrial ruling and just make a broad-brush approach , '' he said .
Scott Roeder is accused of first-degree murder in the death of Dr. George Tiller . Tiller was one of the few U.S. doctors who performed late-term abortions . The Associated Press contributed to this report. Defendant argues breaking the law is better for society than following it . Judge bars Roeder from using the necessity defense in the doctor 's slaying .