PENNSYVANIA - In a case that became a sharp rallying cry for anti-abortion activists, a doctor who was responsible for cutting the spines of babies after botched abortions was convicted Monday of three counts of first-degree murder.

The doctor, Kermit Gosnell, 72, operated a clinic in West Philadelphia, Penn., catering to poor women that prosecutors called a "house of horrors."

The case turned on whether the late-term pregnancies Gosnell terminated resulted in live births. His lawyer, Jack McMahon, argued that because Gosnell injected a drug in utero to stop the heart, the deliveries were stillbirths, and movements that witnesses testified to observing - a jerked arm, a cry, swimming motions - were mere spasms.

But after deliberating 10 days, the jury found Gosnell guilty in the deaths of victims known simply as Baby A, Baby C and Baby D. He was found not guilty of murdering Baby E.

Prosecutors have said they will seek the death penalty when the trial moves into the sentencing phase on May 21.

While abortion rights groups argued that Gosnell operated far outside the legalities and norms of women's health care, abortion opponents seized on the case to raise questions about the ethics of late-term abortion. Put simply, they asked why a procedure done to a living baby outside the womb is murder, but destroying a fetus of similar gestation before delivery can be legal.

"What we need to learn from the Gosnell case is that late-term abortion is infanticide," the columnist Kirsten Powers wrote last week, after kicking off an online furor earlier with a column suggesting that the news media had ignored the case for ideological reasons.

Abortion rights supporters said it was opponents who politicized the trial. What abortion opponents really sought from the trial, they said, was an acceleration of restrictions at the state level to effectively end legal abortion.

Gosnell was also convicted of involuntary manslaughter in the death of a 41-year-old patient, Karnamaya Mongar, who died of an overdose of sedatives. Among lesser charges, he was found guilty of 211 counts of not waiting 24 hours after consulting with a patient before performing an abortion, and guilty of 24 counts of performing an abortion beyond 24 weeks, the limit in Pennsylvania.

Activists on both sides debated whether the deplorable conditions at Gosnell's clinic - including broken equipment, bloodstained recovery chairs and an untrained staff giving anesthesia and other drugs - could be found at other clinics.