The dead included one police officer and two civilians, Colorado Springs Police Chief Peter Carey told reporters about an hour after the suspect had been captured.
All nine surviving victims - five police officers and four civilians - were listed in good condition at area hospitals.
The slain lawman was identified as Garrett Swasey, 44.
The Colorado Springs clinic has been the target of repeated protests by anti-abortion activists, and the President of the Rocky Mountains chapter of Planned Parenthood, Vicki Cowart, suggested that the hatred of abortion in the United States sets the stage for such violence.
At least eight abortion clinic workers have been killed since 1977, according to the National Abortion Federation - most recently in 2009, when abortion doctor George Tiller was shot to death at church in Wichita, Kansas.
Clinics have reported nearly 7,000 incidents of trespassing, vandalism, arson, death threats, and other forms of violence since then, according to the abortion-rights group.
And in recent months, conservatives in Congress have been seeking to cut off federal support for the organization.