The suspect, who has not been named, was picked up and arrested without incident by Johnson County Sheriff Department around 1:15 p.m., local time, law enforcement officials told ABC News. Deputies identified the light blue Ford Taurus, which witnesses saw fleeing the scene, in Gardner, Kan., roughly two and half to three hours away from where Tiller was killed.
Sources close to the investigation described the suspect as a balding white male in his late 50s or 60s.
Authorities were called to the shooting at the Reformation Lutheran Church shortly after 10 a.m., where Tiller was a congregant, according to ABC News Wichita affiliate KAKE. Tiller was pronounced dead at the scene shortly after emergency crews arrived.
Tiller, who ran the Women's Health Care Services clinic, a high-profile abortion clinic in Wichita, was one of the few doctors in the country that still performed late-term abortions. Just this month, Tiller's clinic was vandalized, according to KAKE.
An unidentified woman who answered the phone at Tiller's clinic in Kansas declined to comment or specify whether security measures had been increased in light of Tiller's murder.
Tiller has been a target of anti-abortion violence in the past. In 1985, his clinic was bombed, and in 1993, he was shot in both arms outside the clinic by Rachelle Shannon of Grants Pass, Ore. He testified at Shannon's trial.
In 1994, Tiller said he initially thought rubber bullets had been fired, according to ABC News Radio.
"I looked down at the floor and there's blood all over the place and there's glass all over the place. And I figured I'd been shot," he said.
In March, Tiller was acquitted of 19 misdemeanor charges that he performed abortions illegally, failing to follow state law and obtain a second opinion on late-term abortions.
Under Kansas state law, abortion is legal only when a doctor affirms that the fetus can't live independently outside of the mother's womb, also known as determining viability. If the fetus is viable, two doctors must attest that the abortion is necessary for the well-being of the mother's physical or mental health.
A longtime acquaintance of the doctor from the Wichita Country Club, who did not want to use her name, told ABC News.com that the news of his death was upsetting.
"It infuriates me," she told ABCNews.com. "He was shot in church. He was persecuted by some radical thinking individuals.
"He was well respected in many circles in Wichita and had a presence about him," she added. "You could look at him and tell he was a man of character."
The homicide has shaken up the upper middle class neighborhood of east Wichita, where violence is relatively uncommon.
"Any community is diminished by a homicide ... and Wichita certainly no different than any other community in the country," said Wichita Police Duty Chief Gordon Bashum.
Anti-Abortion Rights Groups Condemn Tiller Killing Operation Rescue, an anti-abortion rights group, which has denounced the practices of Tiller for years and staged mercy demonstrations outside the clinic in the summer of 1991, condemned the murder.
"We are shocked at this morning's disturbing news that Mr. Tiller was gunned down," the organization said in a statement. "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. We pray for Mr. Tiller's family that they will find comfort and healing that can only be found in Jesus Christ."
Pat Turner, 83, member of the Wichita chapter of the Right to Life of Kansas organization and 30 year anti-abortion rights activist who attended protests outside of Tiller's clinic told ABC News.com that the doctor's death was far from what any organization in Wichita prayed for.
"We abhorred all the things that he did, but we don't believe that it's in our power to take someone else's life," she said. "We have prayed and worked to change his heart and change the laws that have been made ... [but] we feel as though he should be judged in the courts. God will have his day of judgment for sure, but it's not up to us to do that."
A statement from Tiller on the Women's Health Care Services clinic Web site offers a window into the doctor's views on abortion and women rights.
"Women and Families are intellectually, emotionally, spiritually, and ethically competent to struggle with complex health issues -- including abortion -- and come to decisions that are appropriate for themselves," Tiller wrote on the clinic Web site.