The regional head of Planned Parenthood has promised to quickly reopen the Colorado Springs clinic where three people were killed and continue to offer health care services.
Vicki Cowart spoke at the first of several vigils planned for victims on Saturday and drew a standing ovation as she walked to the church pulpit.
She said the organisation would learn from the attack, “square our shoulders” and carry on with its mission.
After her remarks, a woman in the audience stood up and objected to the vigil becoming a “political statement” before leaving.
Three people were killed in the attack, including a University of Colorado Colorado Springs police officer, Garrett Swasey. The other two have not yet been publicly identified.
Nine people were taken to hospital after the incident, including five officers.
At least four have since been released from hospital. One of them was Ozy Licano, who was injured when the gunman fired on him in the parking lot. The other three have not been identified.
Speaking at Saturday’s vigil, Ms Cowart said all 15 employees at the clinic survived and worked hard to make sure everyone else got into safe spaces and stayed quiet during the attack.
Earlier, Rev Nori Rost called the gunman a “domestic terrorist”. In the back of the room, someone held a sign that said “Women’s bodies are not battlefields. Neither is our town.”