The only thing that could save Jesse Pomeroy from the gallows was to show that he was legally insane at the time he committed the crimes. "Insanity" is a legal, not medical, term, and this makes the affirmative defense of insanity a risky and difficult position to prove.

The concept of legal insanity is gauged by what are called the "McNaughton Rules" after the case that spawned them. In England during the 1830s, Daniel McNaughton stood trial for killing the secretary to Prime Minister Robert Peel. McNaughton was a lunatic who imagined Peel was part of a conspiracy to kill him although he had never seen the prime minister. McNaughton went to Peel's residence at Downing Street and attacked the first man he saw, who happened to be Peel's assistant.

It was clear from testimony at McNaughton's trial that the man was mentally disturbed and the jury was troubled by this fact. In a bit of enlightened jurisprudence, they didn't want to hang a sick man, and acquitted McNaughton, who was immediately ordered by the court into a mental institution.

The uproar over McNaughton's acquittal prompted the creation of the McNaughton Rules and the concept of legal insanity. The rules created the means by which the jury or judge could establish that a defendant was incapable of understanding the charges against him, unable to assist in his own defense or, more importantly, unaware of the difference between right and wrong at the time he commits the offense. This is the difference between David Berkowitz and John Hinckley. Berkowitz, whose mental defects made him think the devil, in the shape of his neighbor's dog Sam, was ordering him to kill, was mentally ill. He knew, however, that what Sam was telling him to do was wrong and did it regardless of the consequences. Hinckley, on the other hand, did not know it was wrong to shoot President Ronald Reagan to gain the favor of a Hollywood star.

The question for Jesse Pomeroy's lawyers was whether their client was just plain sick or if he was legally insane. For them it was the difference between life and death.

While the press and the public called for his head, the doctors began examining Jesse to find out what was going on inside his mind.

From a biological perspective, crime is a normal behavior. "Crime consists of an act that offends certain very strong collective sentiments," wrote Emile Durkheim in Rules of Sociological Method (1950). Assuming the sentiments existed in every individual -- everyone considered it immoral to steal, for example -- "crime would not ... disappear; it would only change its form, for the very cause which would thus dry up the sources of criminality would immediately open up new ones.

"Imagine a society of saints. Crimes, properly so called, will therefore be unknown; but faults which appear venial to the layman will create there the same scandal that the ordinary offense does in ordinary consciousness."

Montagu, the biologist, refers to this concept of the normality of crime this way: "Criminal behavior is a form of behavior which, like most others, serves the purposes of the organism, but which has been arbitrarily delimited by a social group and termed 'criminal'...The 'criminal' behavior which is socially recognized still remains behavior that from (the criminal's) standpoint, cannot be differentiated from any other normal behavior."

There are some criminals who cannot be reformed. Some choose a life of crime and no threat of punishment can deter them. Others are forced through circumstance to resort to crime as a means of survival. Still others are pathologically unable to get off the track of committing crimes. Jesse Pomeroy was probably one of these last criminal types. When he was released from Westborough, he had not been reformed, nor had his bloodlust been sated.

Three "alienists," as practitioners in the specialty of mental disorders were called back then, examined Jesse -- two for the defense and one for the prosecution. They talked to Jesse for many hours over 14 interviews trying to probe the boy's mind.

Dr. John Tyler became closest to Jesse during the interviews. On their first meeting, Jesse told Tyler all about his history of molesting younger children and blamed the attacks on "a sudden impulse or feeling" which came over him.

Jesse told the alienist that preceding each crime he experienced a sharp pain on the left side of his head which subsequently passed to the right side and then back and forth. The pain prompted the violence, he claimed.

"The feeling which accompanied the pain was that I must whip or kill the boy or girl, as the case was, and it seemed to me that I could not help doing it," Schechter reports Jesse telling the doctor.

Schechter writes that Jesse freely confessed his crimes to the three doctors until he received a note from his mother urging him "not to say I did it unless I did, and to say I didn't if I didn't." He began denying his role in the killings saying he heard a voice in his head calling on him to stand up and defend himself, for he was innocent.

Two months before he went to trial, Jesse recanted his confessions and in a conversation with Tyler, adamantly denied having anything to do either murder. No amount of prodding, then or ever, could change his mind.

The final report issued by Tyler stated that Jesse "envinces no pity for the boys tortured or the victims of his homicide, and no remorse or sorrow for his acts."

He summed up his report by stating two conflicting opinions. First, he said, Jesse could discriminate between right and wrong. Second, he said, the boy was, and forever would be, a threat to society. He needed to be "carefully restrained of his liberty that others might not be endangered." He finished by saying in his opinion, Jesse Pomeroy was insane.