The gunman who stormed the clinic on Friday killed three people and wounded nine others before surrendering to police after a bloody siege lasting several hours inside the facility, authorities said.
Local news media reported that Dear was being held without bail.
The rampage, which took place at a clinic that provides women's health services including abortions, was believed to be the first fatal attack on a U.S. abortion provider in six years. Police have not discussed the suspect's motives.
The assailant in Colorado Springs, Colorado's second largest city, was armed with a rifle when he entered the clinic - a site repeatedly targeted for protests by anti-abortion activists - and opened fire shortly before noon on Friday, authorities said.
University of Colorado Colorado Springs (UCCS) police officer Garrett Swasey, who was killed when a …Police swarming the scene pursued the assailant into the building, trading gunfire with the suspect as authorities tracked their movements from room to room by watching live video feeds from security cameras mounted inside.
Officers closing in on the gunman managed to finally talk him into giving himself up inside, and he was taken into custody more than five hours after the violence began.
Those killed were a police officer and two civilians, Colorado Springs Police Chief Peter Carey told reporters on Friday. All nine surviving victims - five police officers and four civilians - were listed in good condition at area hospitals, he said.
As he has done frequently in cases of recent mass shootings in the United States, President Barack Obama urged measures to make it harder for criminals to get guns.
"We have to do something about the easy accessibility of weapons of war on our streets to people who have no business wielding them. Period," Obama said in a statement on Saturday. "Enough is enough."
The dead policeman in Friday's shooting was identified as Garrett Swasey, 44, a campus police officer for the University of Colorado at Colorado Springs who joined city police in responding to the first reports of shots fired, authorities said. The dead civilians were not named.
At least eight workers at clinics providing abortions have been killed since 1977, according to the National Abortion Federation - most recently in 2009, when doctor George Tiller was shot to death at church in Wichita, Kansas.