Late-term abortionist George Tiller was shot and killed Sunday at Reformation Lutheran Church in Wichita, Kan. Tiller was serving as an usher at the time. A suspect was detained in suburban Kansas City, and Wichita police believe the man acted alone.

Anti-abortion groups have denounced the killing. Operation Rescue President Troy Newman said in a statement, “We are shocked at this morning’s disturbing news that Mr. Tiller was gunned down. Operation Rescue has worked for years through peaceful, legal means, and through the proper channels to see him brought to justice. We denounce vigilantism and the cowardly act that took place this morning.”

President Obama was “shocked and outraged” by the shooting, adding, “However profound our differences as Americans over difficult issues such as abortion, they cannot be resolved by heinous acts of violence.”