Dear, 57, is suspected of entering the clinic on Friday and engaging in a standoff with police that lasted for five hours. One police officer and two civilians died and at least nine were injured.
Suthers said he would not comment on the motive of the shooting or whether the clinic was the intended target. The staff at the clinic were not injured.
"We have a person that's pretty much off the grid and acting for whatever motivation," Suthers told ABC News. "[It's] very hard to ferret out those folks."
Dear, a North Carolina native, lived a reclusive lifestyle in a white trailer in Hartsel, Colo., and "preferred to be left alone," one neighbor told The New York Times.
Planned Parenthood was accused of attempting to profit from the sale of fetal tissue after conducting abortions. An anti-abortion group released videos of members meeting Planned Parenthood representatives while undercover -- videos which the anti-abortion group state are evidence Planned Parenthood sells fetal tissue. The women's health organization said the videos were heavily edited and were not an accurate representation of the organization's practices.
In October, Planned Parenthood said it would stop selling fetal tissue for profit -- a practice that is legal under a 1993 law.
Vicki Cowart, president and CEO of Planned Parenthood Rocky Mountains, told ABC News it seemed the clinic was targeted. She said she believes the recent controversy surrounding Planned Parenthood created a "negative environment" that contributed to the attacks.
"We've seen that across the country from all sorts of speakers in the last few months," Cowart said. "I can't believe that this isn't contributing to some folks, mentally unwell or not, thinking that it's OK to -- to target Planned Parenthood or to target abortion providers."
"The airwaves are full of anti-abortion language, of anti-Planned Parenthood accusations, much of which is false in nature," Cowart continued. "We at Planned Parenthood are first and foremost a health care provider. We provide life-saving services to all kinds of folks, men and women, across our communities, and the tirades against Planned Parenthood in the last few months have really been over the top."
Dear will make his first court appearance on Monday. He is being held without bail at the El Paso County criminal justice center.