The man accused of killing three people and injuring nine others at a Planned Parenthood clinic in Colorado stunned a court by declaring he is a "warrior for the babies".
Robert Lewis Dear, 57, made the outburst before he was formally charged with first-degree murder and other counts in a Colorado Springs court.
Police have declined to discuss a potential motive for the November 27 attack, but there has been mounting evidence to suggest Dear was deeply concerned about abortion.
He rambled to authorities about "no more baby parts" after his arrest, and a law enforcement official said this week that Dear asked at least one person in a nearby shopping centre for directions to the clinic before opening fire.
A first-degree murder conviction can lead to life in prison or the death penalty.
Those killed were Garrett Swasey, 44, a University of Colorado-Colorado Springs officer who rushed to the scene; Ke'Arre Stewart, 29, an Iraq war veteran who was accompanying someone at the clinic; and Jennifer Markovsky, 35, who also accompanied a friend at the clinic.
Five other officers were shot and injured in the rampage.
Colorado Springs mayor John Suthers said on Monday that responding officers rescued 24 people from inside the clinic building and helped remove 300 people from surrounding businesses where they had been hiding while the shooting unfolded.