Protests began in earnest in 1975, and they were fiery, fueled by outrage at the range of abortion care Tiller offered at his clinic. In 1986, not long after Krista went to Women’s Health Care Services for her abortion, a pipe bomb went off, causing more than $100,000 in damage. The perpetrator was never discovered.

Afterward, Tiller hung a sign saying “HELL NO! WE WON’T GO!” and installed extra security—bulletproof glass, the gate and fencing and metal detector, and armed guards, eventually including the same guard who still works there, who remembers Tiller as “a good man” who “didn’t have any fear.” Tiller began wearing a bulletproof vest.

That same year, Operation Rescue was founded, and it immediately ramped up the tactics of the anti-abortion movement. Its leader, Randall Terry, a self-described “former used-car salesman, hamburger flipper and teen-age marijuana user,” deployed strategies including civil disobedience to prompt mass arrests and intense harassment of anyone connected to an abortion clinic. In 1991, Operation Rescue organized the Summer of Mercy, a six-week-long protest focusing on George “Killer” Tiller, as they called him. It was the group’s largest and most lucrative effort, lasting 42 days, resulting in nearly 2,700 arrests, and bringing in an estimated $177,000.

As employees began to face targeted harassment, Tiller started issuing regular staff bonuses, which he dryly referred to as “combat pay.” Sometimes he would tell them that “the only requirement for evil to triumph is for good people to do nothing.” Occasionally, he would shout back at the protesters—he once told Terry that he was sorry his mother hadn’t aborted him.

A housewife and mother named Shelley Shannon, radicalized by a group that called themselves the Army of God and that told its members that murdering abortion providers was morally justifiable, took a bus from her home in Oregon to Wichita. It wasn’t her first act of violence—she’d already committed a string of clinic arsons, following instructions laid out in the Army of God handbook—but this trip would be different. She approached Tiller in the clinic parking lot as he was about to drive off in his 1989 Chevy Suburban. He thought she was going to hand him anti-abortion pamphlets, so he raised his middle finger. She shot him in both arms. He managed to get back inside the clinic, where his staff treated his wounds as Shannon sped off. A clinic staffer had the presence of mind to chase Shannon for long enough to jot down her rental car’s license plate number, and cops picked her up when she arrived in Oklahoma City to return the vehicle. The next day, Tiller was back at work, where he posted another sign outside: “WOMEN NEED ABORTIONS AND I’M GOING TO PROVIDE THEM.”

Sixteen years later, a slender, bald, white man named Scott Roeder—also a member of the Army of God—homed in on Tiller’s church as the place where the doctor would be most vulnerable. Twice, Roeder went to Reformation Lutheran Church for Sunday services, but couldn’t find Tiller. On Roeder’s third visit, Tiller was serving as an usher. Roeder, head bowed, approached. He pulled a gun from his pocket and shot the abortion provider point-blank in the head in his house of worship. Tiller did not survive.

It’s been more than a decade since Tiller was murdered, but at Trust Women, which reopened and rebranded under his protégé Julie Burkhart in 2013, the past has a habit of lingering outside the gates.

Adapted from Becca Andrews’ No Choice: The Destruction of Roe v. Wade and the Fight to Protect a Fundamental American Right, which will be published by Public Affairs in October.