As much as I tried to avoid being taken in by the drama of the Casey Anthony trial, I was jerked alert by its conclusion, the most controversial murder acquittal since that of O.J. Simpson.

Florida jurors found Anthony guilty of four counts of lying to law enforcement officers but acquitted her of the murder of her 2-year-old daughter, Caylee.

Once again, national reaction was as furious as a herd of cats caught in a rainstorm. Once again very big questions are raised about our justice system. Does the jury system work? Are the jurors, sequestered from the wise counsel of TV commentators, less wise and intelligent as those of us who are watching it at home?

Like many others, I concluded that Anthony would be found guilty at least of manslaughter. Her suspicious behavior persuaded me. Fortunately, our justice system requires more than suspicious behavior to win a conviction. As bitter as the pill may be to swallow sometimes, evidence matters.

At least nobody could accuse these jurors, as in the Simpson case, of being bedazzled by racial issues or the star appeal of a celebrity defendant. This jury had other problems to contend with. The most glaring problem was the lack of an exact cause of the young victim's death.

The "Tot Mom," as TV's Nancy Grace dubbed Casey Anthony, failed to report her child's disappearance for a month, until Caylee's grandmother reported the odor of "a dead body" in Anthony's car. Anthony claimed the child had been taken by a baby sitter, who turned out to be a fiction.

When Caylee's body was found two months after her mom was indicted, she had duct tape on her face and her body was badly decomposed. Maggots were found in the trunk of Anthony's car.

Yet despite this and other suspicious clues, as the old saying goes, a trial is a contest to see who has the best lawyer. Anthony's defense lawyers offered a new scenario at her trial, at which she did not take the witness stand. They argued that Caylee died by accidental drowning in her grandparents' pool. In a panic, Anthony's father helped hide the body, including putting duct tape on Caylee's face to make it look like murder, defense lawyers said. Anthony's parents denied these horrors, and other claims that were made against them. Indeed, it still makes little sense to me that Anthony's father, a former police officer, would try to cover up an accident by making it look like a murder.

But in the courtroom contest between dueling narratives, our system grants an advantage to the defense. It puts the burden on the prosecution to prove its case beyond a reasonable doubt.

Caylee's body was so badly decomposed that the cause of death could not be established, raising the prosecutors' burden. It is much more difficult to prove you know why somebody died when you can't quite prove how they died.

It also is not easy for a jury to send a young woman to death row or even a life sentence in prison when they know another narrative is just as plausible as the one prosecutors present.

That lack of certainty left the defense lawyers free to come up with alternative scenarios. Their version only had to be plausible enough to cast a shadow of doubt on the prosecution's version of events.

Cases like this make it hard to stomach a system that would rather let the guilty go free than risk convicting the innocent. But it beats the alternative.