With his death Sunday, George Tiller became the eighth person and fourth doctor slain in abortion-related attacks.
This is the first slaying of an abortion provider in more than a decade.
The most recent killing of an abortion provider took place on October 23, 1998, when New York physician Barnett Slepian was shot in his home by a sniper.
The sniper, James Kopp, fled the country but was caught in 2001. He was convicted of the murder in 2003 and sentenced to 25 years to life.
In July 1994, physician John Britton and his security escort were killed while sitting in their car in the parking lot of a Pensacola, Fla., abortion clinic. Britton's wife was wounded.
Paul J. Hill, an excommunicated Presbyterian minister, was arrested and convicted of the killings. He was executed by the state of Florida in 2003, making him the first person executed for an abortion-related killing.
David Gunn became the first abortion doctor killed when he was shot on March 10, 1993, during an anti-abortion demonstration outside his Pensacola clinic.
Gunn's killer, Michael Griffin, was arrested at the protest and later sentenced to life in prison.
Other attacks on abortion clinics resulted in the 1994 deaths of two receptionists at clinics in suburban Boston.
An off-duty police officer working as a security guard at a Birmingham, Ala., clinic was killed in January 1998 when a bomb left by Eric Robert Randolph, the man responsible for the 1996 Centennial Olympic Park bombing, exploded.