The Scott Peterson Trial:
Can the Prosecution Win This Largely Circumstantial Case?

On June 2, the long-awaited trial of 31-year-old Scott Peterson finally got underway. Peterson, as has been widely reported, is accused of capital murder based on allegations that he killed his wife, Laci, and their unborn son on Christmas Eve 2002.

So far, prosecutors haven't exactly come out swinging. And that is largely because, it seems, they don't have much to swing with.

Conspicuously absent from the prosecution's evidence locker so far is any blood or other bodily fluid evidence consistent with a killing. Indeed, prosecutors have failed to offer any physical evidence linking Scott to the crime. Nor have they come forward with a cause of death for either Laci or the couple's son.

Defense attorney Mark Geragos, by contrast, did come out swinging. In his opening statement, he proclaimed that, "The evidence is going to show clearly, beyond any doubt, that not only was Scott not guilty, but stone-cold innocent." This audacious move meant the defense voluntarily shouldered a burden that legally, it never must bear: The burden to prove innocence.

How does the defense team intend to stay true to its word? The short answer is: Science. As on "CSI," they're hoping the evidence will speak for itself - and in favor of Scott's innocence.

Meanwhile, the prosecution is hoping to build a circumstantial case based on Scott's whereabouts; on testimony as to his demeanor after Laci disappeared; and on evidence that he was unfaithful to Laci, unhappy in their marriage, and unhappy about the coming birth of his son.

In a contest between scientific and circumstantial evidence, it's very likely that science will win out. Unless there is some shocking new development, we can expect an acquittal in the Peterson case.

The Importance of the Evidence As To Whether Laci's Baby Was Born Alive

What scientific evidence will the defense present? Centrally, the defense contends that forensic evidence will show that the couple's unborn son, whom they had planned to name Conner, was born alive sometime after Laci went missing.

Geragos told the jury, "If this baby was born alive, clearly Scott Peterson had nothing to do with this murder." He promised that "[t]he evidence is going to show that [Laci] was alive on December 24, when Scott went to the marina."

It's highly unlikely that Geragos would make such a promise if he couldn't keep it. After all, he's an experienced advocate, and breaking promises to the jury is probably the single biggest no-no in the realm of trial advocacy.

And so far, the reported evidence seems to be on Geragos' side. Laci went to the doctor the day before her disappearance. At the time, the fetus was estimated to be 32 weeks old.

The bodies were discovered on April 17, 2003. The medical examiner who performed the autopsies on the bodies after that date estimated the fetus' gestational age at 9 months, which would be just less than 39 weeks. And he could not rule out the possibility that the fetus had been born alive. Similarly, a forensic anthropologist measuring the baby's body's bones estimated Conner's gestational age at 33 weeks to 38 weeks.

This evidence is pivotal - and very problematic for the prosecution. Presumably, for Conner to continue to develop for one to seven weeks after the doctor's appointment - as the evidence shows -- he would have had to either have remained in a living Laci's womb for that period of time, or been born alive and continued to live on.

But the prosecution's claim is that the unborn baby and Laci both died a day after the doctor's appointment. How can that be reconciled with the 39 week, and 33-38 week estimates?

Could Scott have killed his wife and unborn child after the investigation began? Highly unlikely - as soon as Laci disappeared, he was under an intense police microscope.

The best way to reconcile the evidence is the one Geragos offers: Either Conner was born alive, or Laci lived on, and Conner developed in her womb, for at least a week after December 24, when the prosecution claims she was murdered.

In sum, the prosecution may be devastatingly undermined by evidence provided by the state's own medical examiner and forensic anthropologist.

The Prosecution's Case: Based on Demeanor, Whereabouts, and Possible Motive

The prosecution would be facing an uphill battle even if it didn't have this huge evidentiary setback. So far, as noted above, the prosecution's case against Peterson has been based on testimony as to circumstances, whereabouts, motive, and demeanor. But this kind of evidence, by itself, can't replace the lack of physical or scientific evidence favoring the prosecution.

As has been widely reported, Peterson's solitary fishing trip, on the day his wife disappeared, placed him precisely where the bodies washed ashore. But this coincidence is less striking than it may seem. Of course Peterson, if he went fishing, would have gone to the marina. Of course the killer - even if he was not Peterson - might have thought that an ideal place to dispose of a body would be the nearby marina.

In addition, Peterson's prior affair with Amber Frey, and well as other evidence, does suggest he was unhappy with the status of husband and father - and that he might have had motive to kill the pregnant Laci. But there are many unfaithful men out there who complain to their mistresses about their wives, and stay married. While Scott's unhappiness may have been motive for the affair, and perhaps even divorce down the road, it alone is not motive enough for murder.

Then there's the demeanor evidence. So far, in the first two weeks of trial, five witnesses have testified that Peterson's demeanor was hardly that of a grieving spouse during the days and weeks following Laci's disappearance. The witnesses - drawn from the Petersons' family and friends - testified that Scott seemed standoffish, often evading questions, and when he did speak, he seemed "odd."

Scott's attitude, witnesses say, was sullen - or simply devoid of emotion. For instance, Harvey Kemple testified that "I saw more emotion out of [Scott] when he burnt the damn chicken [several months before Laci's disappearance] than when his wife was missing."

This demeanor evidence, however, is weak. Some of the witnesses are relatives of Laci who have been suspicious of Scott from the start - and perhaps never liked him much in the first place. If they didn't perceive him as an ideal husband when she was alive, how likely is it that they'd see him as ideal after she disappeared - and after they learned of his extramarital affair?

How Would An Innocent Spouse Supposedly Behave?

More fundamentally, as jurors will doubtless know, different people respond to grief and trauma in very different ways. Just how is an innocent spouse-turned-suspect supposed to behave?

Consider three notorious cases of accused wife-murderers (or near-murderers) who were acquitted - and how these men behaved after the crime. These examples make it clear that defendants don't get convicted because their demeanor evidences likely guilt. These examples also open up the possibility that some among the three were acquitted because they actually were innocent, and that even an innocent man can react to his wife's death or disability with a demeanor that some observers find suspicious.

First, there's O.J. Simpson. Simpson fled in the infamous Ford Bronco chase - at times holding a loaded gun to his head. Though many still believe he was guilty, and that his fleeing was a tacit admission of guilt, a criminal jury disagreed. Also, what is typically cited now as the reason he should have been found guilty is scientific, physical evidence - DNA and blood - not his demeanor, bizarre or otherwise, near the time of the crime.

Second, there's the Claus von Bulow case - later the basis for the film "Reversal of Fortune." Like Scott Peterson, von Bulow was accused of callous indifference in the wake of the total disability of his wife, Sunny -- who lapsed into a permanent vegetative state, allegedly as a result of his murderous insulin injection. In that case, the prosecution also offered evidence that, on an earlier occasion, von Bulow refused to call a doctor when his wife was so ill she fell into a temporary coma. But von Bulow, too, was acquitted - though only after a second trial.

Third, and most similar to the Peterson case, is the 1954 case of Dr. Sam Sheppard - later the basis for the film "The Fugitive." Sam Sheppard woke one July morning to find his young, pregnant wife, still in their bed, beaten beyond recognition. Dazed and himself injured, he followed the "form" of a "bushy haired" intruder out onto a nearby beach, where the doctor was knocked unconscious.

At first, the press and other members of Sheppard's small Ohio community consoled the good doctor over his tragic loss. But, just as happened in Peterson's case, it didn't take long for public sentiment to change. Sheppard's affair with a younger woman was revealed, and it was revealed, too, that they had discussed his possibly divorcing his wife. (In contrast, Peterson reportedly did not even tell Amber Frey of Laci's existence.)

Yet Sheppard's demeanor could be classified as cooperative. He gave statements freely (perhaps too freely) to police. He wept over the loss of his wife. He painstakingly tried to recall details of the murderous night.

In 1956, at his first trial, Sheppard was acquitted of capital murder, but convicted of a lesser charge: murder in the second degree. Ten years later, Dr. Sheppard was retried, and found not guilty.

What, if any role, did each of these defendants' demeanor play in his respective prosecution and ultimate acquittal? In the end, it's hard to say, especially since it seems likely that much more physical evidence was admitted at these defendants' trials, than is expected to be admitted against Scott Peterson.

But one lesson can be learned: A "suspicious demeanor" is more likely to satisfy the "probable cause" needed for arrest, than the "beyond a reasonable doubt" standard needed to convict.

As I noted in a prior column, the husband is virtually always going to be a suspect in his wife's murder (especially if it seems she was murdered in or near their house), and he'll probably be arrested no matter what his demeanor. In addition, there will always be something about his demeanor that can be deemed "suspicious."

The husband is in a Catch-22, after all: If he is cooperative, why isn't he disabled by grief? If he's uncooperative, why isn't he able to pull himself together to help solve the crime?

The Likely Outcome, Based on What Is Known Now, Is Acquittal

My guess is that we are in for some very convincing defense expert testimony as to the gestational age of Conner. If the evidence weren't strong, Geragos would never have put so much reliance upon it. Being able to draw on the evidence of the state's own medical examiner ought to help his case greatly too.

If the defense can show Conner continued to develop after the day prosecutors say the fetus died, that will be devastating. It's possible the prosecution may yet pull a new rabbit out of its hat, but I doubt it. With science on his side, Scott Peterson may soon enjoy his own reversal of fortune.