John Grisham: Teresa Lewis didn't pull the trigger. Why is she on death row?

Although much of this went unchallenged at Lewis's sentencing hearing, it has since been challenged on appeal. Lawyers for Lewis have presented evidence that:

(1) She has an IQ of just above 70 -- borderline retarded -- and as such lacks the basic skills necessary to organize and lead a conspiracy to commit murder for hire;

(2) She has dependent personality disorder and therefore complied with the demands of those upon whom she relied, especially men;

(3) Because of a long list of physical ailments she had developed an addiction to pain medications, and this adversely affected her judgment; and

(4) She had not a single episode of violent behavior in the past.

Her lawyers have also argued that Shallenberger, who committed suicide behind bars in 2006, masterminded the murders. They have pointed to evidence that he had an IQ of 113 and was known to be intelligent and manipulative.

They have cited the sworn affidavit of a private investigator who interviewed Shallenberger in prison in 2004. This investigator said Shallenberger described Lewis as not very bright and as someone who could be easily duped into a scheme to kill her husband and stepson for money. According to the investigator, Shallenberger said: "From the moment I met her I knew she was someone who could be easily manipulated. From the moment I met her I had a plan for how I could use her to get some money."

Lewis's lawyers have also cited a letter Shallenberger sent to a girlfriend shortly after he was sentenced, in which he wrote, "I figured why go to New York for $20,000 a hit when I could do just one and make $350,000 off of it." In the same letter he said of Lewis: "She was exactly what I was looking for."

In addition, they have cited a 2004 affidavit by Shallenberger's fellow assassin, Fuller, who said this: "As between Mrs. Lewis and Shallenberger, Shallenberger was definitely the one in charge of things, not Mrs. Lewis."

Under Virginia law, Lewis, Fuller and Shallenberger are all guilty of murder.

Why, then, did the triggermen get life without parole while Lewis received a sentence of death? Ostensibly, it is because she was the ringleader and thus more culpable. But what could make a killer more culpable than repeatedly shooting a sleeping victim?

Lewis has appealed her case to the U.S. Supreme Court, but her chances do not look good. Her lawyers have also filed a petition for executive clemency with Gov. Bob McDonnell's office; they are, as of this writing, awaiting a decision.

In this case, as in so many capital cases, the imposition of a death sentence had little do with fairness. Like other death sentences, it depended more upon the assignment of judge and prosecutor, the location of the crime, the quality of the defense counsel, the speed with which a co-defendant struck a deal, the quality of each side's experts and other such factors.

In Virginia, the law is hardly consistent. There have been other cases with similar facts -- a wife and her lover scheme to kill her husband for his money or for life insurance proceeds. But there is no precedent for the wife being sentenced to death.

Such inconsistencies mock the idea that ours is a system grounded in equality before the law.

John Grisham's latest novel is "The Confession," forthcoming in October. He lives near Charlottesville.