(CNN) -- The man convicted of killing Kansas abortion provider Dr. George Tiller last year was sentenced Thursday to life in prison without parole eligibility for 50 years.

Scott Roeder, 52, was facing a minimum mandatory life sentence, but a Kansas judge had the power to decide whether he could be eligible for parole after 25 years or after 50.

"The blood of babies is in your hands," Roeder said as he was escorted from a Wichita, Kansas, courtroom on Thursday evening, referring to the district attorney who prosecuted him.

The Tiller family praised the sentence in a statement Thursday night.

"It is the most severe penalty available ... under Kansas law," the family said. "This crime was cruel and heinous not only because it took our husband, father and grandfather, but because it was a hate crime committed against George -- [and] also against all women and their constitutional rights."

Roeder was convicted in January of murdering Tiller, who operated a clinic in Wichita, Kansas, where late-term abortions were performed. Tiller was shot to death in May in the foyer of Reformation Lutheran Church in Wichita as Sunday services began.

Speaking before his sentencing, Roeder blasted Tiller, quoted the Bible at length and argued the slaying was justified because he was protecting the unborn.

"You have the power to acquit and if you were to obey the higher power, God himself, you would acquit me," Roeder told the judge, Warren Wilbert, before the sentence was handed down.

The sentence included an additional 24 months in prison for two aggravated assault convictions related to Tiller's murder.

Abortion rights groups praised the sentence on Thursday.

"[The] decision makes it crystal clear that there is no justification for vigilante violence against health care providers who perform abortions," said Cecile Richards, president of Planned Parenthood Federation of America. "Others who may harbor such plans have been put on notice that violent attacks by anti-choice extremists will be prosecuted to the fullest extent of the law and punished decisively."

Before the sentence was handed down, Roeder said in court Thursday that he agonized over the decision to kill Tiller, but said the act was done so that the doctor could not "kill again."

"It was the most agonizing and stressful decision I have ever had to make, and it took years to come to this conclusion, especially with the knowledge that I may never see my son, my daughter or my family again," Roeder said at his sentencing at the Sedgwick County Courthouse.

"It is the duty of the state of Kansas to protect all of the people, including those whom George Tiller killed. Had the courts acted rightfully, I would have not shot George Tiller," he said.

"The blame for George Tiller's death lies more with the state of Kansas than with me," he said. He spoke quickly and clearly.

Earlier in the sentencing, Tiller's attorney, Lee Thompson, spoke on behalf of the slain doctor's family, saying that Tiller's killing was "domestic terrorism" that robbed a family of a husband, father and grandfather.

"This man was devoted to his family. ... He was very important, and they are desperately sorry and grieving over his loss," Thompson told the court.

"He's committed an act of terrorism, a heinous, atrocious, cruel murder planned, plotted and devised for years and years and designed and executed solely for the purpose of killing someone with whom he disagreed," Thompson said.

Prosecutors argued for life in prison without the opportunity for parole until after 50 years.

"I believe he should be given the longest sentence possible," District Attorney Nola Foulston said Thursday.

But Mark Rudy, an assistant public defender, said there were no aggravating factors to warrant the "hard 50." He told the judge that he and the defense team offered condolences to Tiller's family and asked that "you follow the law."

Wilbert, the judge, said that the aggravating factors included the fact that Tiller was shot in his church.

"Reformation Lutheran Church was not holding Tiller accountable for his sins," Roeder responded. "They were not a true church. ... It was a synagogue of Satan, as the Bible talks about."

After Roeder had spoken for about 40 minutes about what he said was the biblical justification for the killing, Wilbert stopped him. "I'm sorry, I'm not providing you a forum for an all-night dissertation on the political debate on the issue of abortion," Wilbert said.

Eugene Frye, who spoke Thursday on Roeder's behalf, said he has known and prayed with him since the mid-1990s and described him as polite and courteous. He said Roeder "could and would" spend hours discussing abortion and the Bible.

"I know Scott's character cannot be separated from abortion," he said in asking for the lesser sentence.

During his trial, Roeder testified he believed he had to kill Tiller to save lives and said he had no regrets.

"There was nothing being done, and the legal process had been exhausted, and these babies were dying every day," he said. "I felt that if someone did not do something, he was going to continue."

George Hough, a psychologist who examined Roeder at the behest of the defense, said Roeder was competent. "He did know what he was doing," Hough said.

Roeder felt justified and didn't feel guilty, Hough said. Roeder believed there was a higher law, God's law, according to Hough.

In closing arguments, prosecutor Ann Swengel called Roeder's testimony "chillingly horrific" and said he carried out a "planned assassination."

Prosecutors initially fought to keep abortion out of the trial, saying that Tiller's death was a straightforward case of premeditated murder.

Eventually, the abortion issue took center stage as prosecutors portrayed Tiller as a target of Roeder's anti-abortion agenda, and defense attorneys attempted to mitigate his culpability under the theory that he believed Tiller's death was justified to save the lives of others.

Defense attorney Steve Osburn said after the verdict that Roeder "feels remorse toward the family, but not for what he did."

The trial drew activists from both sides of the abortion debate to the courtroom, and a van plastered with slogans and photos of fetuses was parked in a prominent spot in front of the courthouse.

Among the attendees were the Rev. Michael Bray, whose history in the anti-abortion movement includes 1985 conspiracy convictions in connection with a string of clinic bombings, and Katherine Spillar, executive vice president of the Feminist Majority Foundation.

Congregants from Reformation Lutheran testified they had seen Roeder at church several times before the day he killed Tiller by shooting him at point-blank range in the head.

Roeder's defense team did not dispute much of the evidence. Roeder testified he chose to target Tiller at church because it presented the best "window of opportunity" to attack the doctor, who traveled in an armored vehicle and whose clinic was a "fortress."

Speaking about the church Thursday, Hough said it was the only place where Roeder felt Tiller was vulnerable. "It solved his access problem," he said.