Flanagan capitalized on their uncertainty, asking each one whether the determination of viability should not be left up to the fetus itself, no matter how statistically tiny its chance. The doctor's role, he said, is simply to give it the best medical care as it struggles for life.
Roe and Doe also did not specifically define abortion, leaving another open question whose answer could affect Edelin's fate. If abortions presuppose the death of the fetus, as Edelin claimed, then his entire procedure was legal and immune from prosecution. But Flanagan's medical experts insisted that an abortion was nothing more than the termination of pregnancy, which could sometimes result in a live birth.
The definition of birth itself became pivotal as witnesses raised questions of fact about the procedure Edelin used and the exact moment the fetus died, Doctors testifying against him agreed that birth means the separation of the placenta from the wall of the womb, the moment at which the fetus "goes on its own systems" for nourishment and oxygen. Defense witnesses repeated the more commonly understood definition of the word as involving expulsion or removal from the mother's body. And Judge McGuire supported that understanding of the word in his charge to the jury.
The distinction was crucial, for Edelin was accused of killing the aborted fetus before removing it from inside its mother. Flanagan charged that he held it motionless inside the womb and watched a wall clock for three minutes as it struggled for air and died. Edelin, supported by testimony from two nurses and a medical student, denied the three-minute wait, and claimed that in fact there was no working wall clock for him to watch. But he did not deny that he had no intention of delivering a live baby: "It would have been contrary to the wishes of the mother."
Although Flanagan's only eyewitness had testified emphatically that "the baby was dead" when Edelin finally removed it, the prosecutor brought other witnesses who claimed it had breathed outside its mother. On the basis of their examination of its lungs, a medical examiner and a pathologist testified that the fetus could have drawn breath outside its mother.