In 1994, John Salvi III shot and killed two abortion clinic workers and wounded five others during attacks on two separate Planned Parenthood clinics in Brookline.
In response to those attacks, the Legislature passed a law that created a 6-foot floating buffer zone around patients and an 18-foot buffer around clinic entrances.
In 2007, Gov. Deval Patrick signed a bill that created a firm 35-foot buffer zone around entrances, exits and driveways of abortion providers.
Last week, the Supreme Court agreed to hear a challenge to that law, brought by abortion opponents who claim that the buffer zone infringes on their right to free speech.
Martha Davis, law professor at Northeastern University.