"I think the Scott Roeder that I know is a very pleasant and intelligent young man," said Dinwiddie, reached at her home in Kansas City, Mo.
Asked whether she thought Roeder was capable of murder, Dinwiddie said that she doesn't think Tiller's death was murder.
"I don't think whoever shot Tiller shot anybody," Dinwiddie said. "I think Tiller was stopped from killing the babies that would have died today. I think whoever shot him just stopped a cold blooded serial murderer in their tracks."
Dinwiddie said that she knew Roeder did not "like people killing babies," but was "very pleasant" and had a "good heart."
Roader's ex-wife, Lindsey Roeder, told police searching her home Sunday that her husband was likely involved in Tiller's death.
Lindsey Roeder said it was Scott Roeder's strong anti-abortion views that led to the couple's 1996 divorce. She said her ex-husband never kept quiet about his views on abortion.
"My family does not condone or support what Scott has done. This event is a tragic and senseless one and our thoughts and prayers are with the congregation and the doctor's family," Lindsey Roeder said.
Lindsey Roeder said Scott Roeder was adamant about seeing his 22-year-old son, Nick, Friday night. She claimed their son has tried to avoid his father and only saw him about once every six weeks growing up.
"My son is only related to his father by blood and does not believe in any of the same views his father does," Lindsey Roeder said.
The two did meet Friday night, she said, and she believes the meeting was meant as a goodbye from father to son.
Tiller's lawyer and friend, Lee Thompson, told "Good Morning America" today that Tiller, 67, was "one of the most positive and courageous men I've ever known."
Thompson said Tiller had a sort of "servant" attitude toward his patients, believing that helping women in distress was his duty even though he often wore a bulletproof vest to work and drove an armored car.
"Dr. Tiller always said he fell in love with the doctor-patient relationship," he said.
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. Earlier this month, Tiller's clinic was vandalized, according to reports.
Tiller has long been a target of anti-abortion activists. His clinic has often been the scene of nonviolent protests, but he was also shot outside his clinic in 1993 and his clinic was bombed in 1985.
In a 1991 interview, Tiller said he had a right to go to work each day.
"What I'm doing is legal. What I am doing is moral. What I'm doing is ethical," he said. "And you're not going to run me out of town."
Tiller is believed to be the first abortion doctor to be killed since Barnett Slepian was assasinated in Amherst, N.Y., in 1998.