Robert Dear, 57, faces 179 charges for the attack that killed two civilians and a police officer, and wounded nine.
During the hearing, he was formally charged with first-degree murder. The Planned Parenthood group has drawn anti-abortion protests in the past.
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Dear said something about "no more baby parts" during his arrest and had asked for directions to the clinic prior to the attack. "You`ll never know what I saw in that clinic. Atrocities. The babies. That`s what they want to seal,`` Dear said during the hearing.
Those who were killed in the attack include police officer Garrett Swasey, 44, Iraq War veteran Ke`Arre Stewart, 29, and Jennifer Markovsky, 35, who was taking a friend to the clinic.
Police have not discussed a motive in the shooting despite signs that Dear was concerned about abortion, a service provided by Planned Parenthood, a national family planning clinic.
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