Casey Anthony trial: As it draws to a close, deep mysteries remain

In the Casey Anthony murder trial, there's been no confession, no eye witnesses, and no direct physical evidence capable of telling the tale with scientific certainty. Closing arguments begin Sunday.

On the eve of closing arguments, the Casey Anthony murder trial is ending exactly as it began – shrouded in mystery over what really happened to Ms. Anthony’s two-year-old daughter, Caylee.

Nearly 100 individuals testified and more than 400 pieces of evidence were presented to the jury in a month-long trial. But it is still unclear precisely how the toddler died.

There’s been no confession, no eye witnesses have come forward, and investigators have found no direct physical evidence capable of telling the tale with scientific certainty.

IN PICTURES: Key players in the Casey Anthony

Nonetheless, on Sunday morning in the Orlando courtroom of Chief Judge Belvin Perry, prosecutors will attempt to sidestep that glaring hole in their case while urging a jury of five men and seven women to find Casey Anthony guilty of the premeditated murder of her daughter.

If convicted, she faces a possible sentence of death by lethal injection.

Prosecutors have presented a theory that Ms. Anthony used chloroform to subdue her daughter and then murdered her by pressing pieces of duct tape over her mouth and nose.

They say she hid the body in the trunk of her car for several days until it began to decompose and smell. Then she dumped it in a wooded area about a quarter-mile from the family home. The skeletal remains were discovered six months later in December 2008.

Defense claims accidental drowning

In contrast, the defense theory is that Caylee accidentally drowned in the family’s swimming pool and her mother panicked. Rather than call 911, they say Casey and her father, George Anthony, engaged in a cover up to make the death look like the result of a kidnapping.

George Anthony denies any knowledge of how his granddaughter died or that he played any part in a cover up. Casey Anthony declined to testify at the trial.

Both the prosecution theory and defense theory share the same weakness – there is no evidence proving one way or the other that the child’s death was an accident or an intentional act of murder. Instead, both the prosecution and defense cases are framed around circumstantial evidence that might point the jury one way or the other.

That’s why Sunday’s closing arguments are particularly important and could be decisive in whether Ms. Anthony is sentenced to death, receives a lesser punishment, or is acquitted.

Although the defense faces no legal obligation to prove or disprove anything in the case, Defense Attorney Jose Baez made shocking claims of sexual abuse and a cover up during his opening statement, many of which remain unproved. The danger for the defense is that jurors may hold it against Mr. Baez and his client.

But the real focus during jury deliberations, as Chief Judge Perry will instruct, must be on whether state prosecutors proved their case beyond a reasonable doubt.

Key evidence

Among key pieces of evidence in the case:

DUCT TAPE – Prosecutors say the murder weapon was three pieces of duct tape, six to eight inches long, recovered near Caylee’s remains. Because some of the tape was found still attached to a mat of Caylee’s hair, they say it must have covered her mouth and nose and ended her life by suffocation. In a controversial move, prosecutors showed the jury an animated video of Caylee’s skull and face with pieces of duct tape superimposed over the image in various positions to show how it might have covered both her nose and mouth.

Defense attorneys objected to the video, saying it was meant to inflame the jury. They say no fingerprints were recovered on the tape and the only unidentified DNA detected on the duct tape excluded Casey Anthony as the donor. They add that there is no proof that the tape covered both the mouth and nose. If the tape only covered the mouth it could not be a murder weapon.

CHLOROFORM – A research scientist at the Oak Ridge National Laboratory in Tennessee detected traces of chloroform in the trunk of Ms. Anthony’s 1998 Pontiac Sunfire. Prosecutors say the evidence suggests that Ms. Anthony drugged her daughter with chloroform before killing her with duct tape. In addition, someone conducted Internet searches on the Anthony’s home computer for the words “chloroform,” and “how to make chloroform.” The searches were conducted when both of Ms. Anthony’s parents were at work.

Defense attorneys counter that Caylee’s remains were tested for the presence of chloroform and other drugs and no toxic substances were detected. They suggest the computer searches were done for curiosity because one of Casey’s friends had posted a gag photo showing a man and woman in a romantic restaurant with the caption: “Win her over with chloroform.” They say investigators never recovered any chemicals, mixing materials, or receipts related to the making of chloroform. Also, an expert in chemical analysis testified that chloroform is present in many household items, including bleach, and could have been in the trunk from an innocent source.

HAIR – A single nine-inch strand of hair was discovered in the trunk of Casey’s car. An FBI forensic expert said the hair was consistent with Caylee’s hair and that it showed signs of having come from a decomposing body. The same expert admitted on cross-examination that trying to identify hair as having come from a decomposing body is still an evolving area of forensic science.

SMELL – Several witnesses – including Casey’s father, George – testified that the lingering foul odor in Casey’s car in the summer of 2008 was the distinct smell of human decomposition. A cadaver dog signaled its handler that a dead body might be in the trunk. A research scientist at the Oak Ridge National Laboratory tested the molecular makeup of the odor and found it consistent with chemicals disbursed from a decaying human body.

In contrast, a University of Central Florida chemist tested the same odor from the car trunk but said he could not say conclusively that the detected compounds indicated the presence of human decomposition. He said there were other environmental sources that might produce the same compounds. An expert in forensic chemistry at Florida International University said the Oak Ridge tests were too experimental and were not reliable enough to be entered as evidence in a criminal trial. Findings like those from the Oak Ridge research have never before been entered as evidence in a criminal case.

Could Caylee have gone into the pool?

SWIMMING POOL – The defense presented a series of photographs demonstrating that Caylee enjoyed swimming and was always eager to jump into the pool whenever given the opportunity. Casey’s mother, Cindy Anthony, testified that on June 16, 2008 she returned home from work and was alarmed to discover the ladder to the above-ground swimming pool was in place and that a side gate leading to the backyard was open. The defense also showed a photo of Caylee apparently opening a sliding glass door to the backyard on her own.

A prosecutor asked Mrs. Anthony whether Casey had ever told her there had been a fatal accident in the pool. Cindy Anthony said her daughter had not. “In fact she continued to assert to you that the child was kidnapped by a baby sitter,” the prosecutor asked. “That’s correct,” Mrs. Anthony replied.

LIES – Casey lied to her friends, family, and the police concerning the whereabouts of Caylee. In late June and early July 2008, Casey told her friends and her mother that Caylee was with a nanny. Casey spent much of that time with her new boyfriend, partying at nightclubs, on shopping excursions, and getting a tattoo that read “Bella Vita” – Italian for beautiful life. Later, as questions about Caylee persisted, she said that Caylee had been kidnapped by the nanny. Investigators quickly determined that the nanny did not exist. They also discovered that Casey had falsely claimed to be working at Universal Studios.

Defense claims Casey Anthony had been abused

Defense attorneys had argued in their opening statement that Casey’s lies and her cold behavior after Caylee was missing were a product of years of sexual abuse by her father and brother. No evidence of such abuse was presented to the jury. During testimony, George Anthony denied ever abusing his daughter. It is unclear whether the defense will raise the issue during their closing argument.

ROY KRONK – Defense attorneys sought to suggest to the jury that Caylee’s skeletal remains had been moved or at least disturbed by the county meter reader, Roy Kronk, who called authorities on December 11, 2008 to report that he’d found a small skull in a wooded area near the Anthony’s house. What makes Mr. Kronk a wild card in the case is that he actually found the remains four months earlier in August, but police never followed up by checking the location.

In testimony, Kronk admitted that he moved the skull slightly with his meter reading stick and briefly picked up a bag of Caylee’s remains, but he denied moving evidence from the site or otherwise altering the evidence. The suggestion was that Kronk was hoping to collect a $255,000 reward for finding Caylee. But the reward was only offered for the safe return of the toddler.

IN PICTURES: Key players in the Casey Anthony