THE MORNING OF December 30, 1994, was a normal day in Brookline, Massachusetts. The local offices of Planned Parenthood, a national organization that provides reproductive health services, including abortion, had opened on time. Employees were just beginning their workday. Shortly after 10 A.M., a man dressed in black came into the office and asked, "Is this Planned Parenthood"" When told that it was, he pulled out a rifle and opened fire.

The receptionist, Shannon Lowney, was killed. Three people sitting in the waiting room were wounded. Amid the chaos, the mysterious shooter disappeared through the door and was gone. About ten minutes later, he entered another office nearby. This office, Preterm Health Services clinic, also provided abortion services. According to a witness, "A man came in with a black duffel bag. He took out a rifle. He said, `Is this...