Prosecutors had alleged that in 2003 Tiller had received second opinions from a doctor who was essentially an employee of his, not independent, as state law requires. But a jury took only about an hour to find him not guilty of all 19 counts.

Tiller, who could have faced a year in jail for even one conviction, stared straight ahead as the verdicts were read, with one of his attorneys patting his shoulder after the decision on the final count was declared. His wife, seated across the courtroom, fought back tears and nodded. The couple declined to speak to reporters afterward.

An attorney for Tiller, Dan Monnat, said the doctor was relieved but noted that he still faces opposition from anti-abortion groups.

Prosecutor Barry Disney said it was "a case that needed to be tried for the community, for everyone to have resolved."

Tiller, 67, has claimed that the prosecution was politically motivated. Phill Kline, an attorney general who opposed abortion rights, began the investigation into Tiller's clinic more than four years ago. But both his successor, who filed the criminal charges, and the current attorney general support abortion rights.

Mary Kay Culp, executive director of Kansans for Life, said abortion opponents were never confident that Tiller would be prosecuted aggressively enough by Steve Six, the current attorney general.

"Even if Tiller had been found guilty, he would have appealed to the Supreme Court," Culp said, noting that four of the Kansas high court's seven justices were appointed by Democratic Gov. Kathleen Sebelius, who supports abortion rights.

Soon after the verdict was announced, the state's Board of Healing Arts made public a complaint against Tiller on allegations similar to those at issue in the criminal case. The complaint was filed in December but not released until Friday.

The board, which regulates doctors, could revoke, suspend or limit Tiller's medical license, or fine him.

Monnat said they have known about the pending administrative matter since it was filed. He said that in many respects it mirrors the criminal accusations of which Tiller was found not guilty.

"With Dr. Tiller's acquittal today, we will now be able to give our full attention and cooperation to the Board of Healing Arts in order to work together toward a similar resolution of this administrative matter," Monnat said.

Kansas law allows abortions after a fetus can survive outside the womb only if two independent doctors agree that it is necessary to save a woman's life or prevent "substantial and irreversible" harm to "a major bodily function," a phrase that has been interpreted to include mental health.

Physician Ann Kristin Neuhaus provided second opinions on late-term abortions before Tiller performed them.

The complaint before the healing arts board cites 11 late-term abortions Tiller performed in 2003 on patients ranging in age from 10 to 18. It alleges that Tiller and Neuhaus had financial or legal ties that violated the law.

Board spokeswoman Kristi Pankratz said the agency would move forward with the disciplinary petition despite Tiller's acquittal. No hearings have been scheduled yet, she said.

According to testimony at his criminal trial in Wichita, Tiller's patients paid Neuhaus $250 to $300 in cash for providing the consultation. The only way patients could see her was to make an appointment with Tiller's office.

In closing arguments, prosecutors portrayed Tiller as a smart businessman who intentionally created an illegal relationship with Neuhaus to make his clinic a "one-stop shop" for late-term abortions. The defense sought to show he was a caring physician concerned about the convenience and safety of his patients.

Tiller testified that he used Neuhaus based on advice from his lawyers and from Larry Buening, who was then executive director of the Board of Healing Arts.

Prosecutors tried to show that Tiller ultimately relied on his lawyers' advice -- an important distinction because the judge told attorneys before their opening statements that relying on the advice of an attorney cannot be used as a legal defense to criminal charges. They also questioned Tiller about the conversation with Buening, noting that Tiller had testified that Buening said he couldn't quote him.

Tiller also testified that in about five cases each year, Neuhaus would disagree with him about the necessity of a late-term abortion. When she declined to concur, the abortion was not done, he said. Tiller estimated that he performed 250 to 300 late-term abortions in 2003.

Kline, the former attorney general who started the investigation, expressed frustration at the prosecutors who tried the case, noting that their only witness was Neuhaus.

"You do not win cases nor achieve justice by calling one witness and ordering your staff not to initiate any additional effort to gather evidence," Kline said in a written statement.

But Disney said his office thoroughly investigated the case and obtained all of Tiller's bank records and other available evidence.

"We presented all the evidence that there was," he said.