Did Prosecutors in the Casey Anthony Murder Trial 'Over-Try' Their Case?

Prosecutors in the Casey Anthony murder trial rested their case Wednesday, but legal experts are questioning whether they "over-tried" the case, effectively giving the defense team ample opportunity to challenge evidence and appeal a possible conviction.

For weeks, the state meticulously laid out a plethora of evidence they say proves the Orlando mother killed her 2-year-old daughter, Caylee, in 2008.

But legal analysts say some of that evidence, including police interrogation recordings and “air samples” taken from Anthony’s car, may have botched the prosecution’s case.

“I think she’ll be convicted, but the conviction will be overturned on appeal because the prosecution foolishly asked the court to consider evidence that was unconstitutional, irrelevant and prejudicial,” said Judge Andrew Napolitano.

Anthony, 25, is accused of first-degree murder in the death of her daughter, whose remains were found five months after she was reported missing. Anthony has pleaded not guilty.

Prosecutors claim Anthony killed Caylee by suffocating her with duct tape over her nose and mouth, while the defense says the child drowned accidentally in the family pool. No cause of death has ever been determined.

The state built their mostly circumstantial case on Anthony's conduct and the lies she told about her daughter's whereabouts. Anthony waited 31 days to report the child missing, for example, and claimed the toddler was taken by a made-up babysitter.

Prosecutors also relied on forensic testimony, including smells of human decomposition in Anthony's car, searches on her computer for terms such as “chloroform” and duct tape found on the girl's skull.

But legal experts, like Houston criminal defense attorney Nicole Deborde, say the introduction of some of that evidence, including a novel forensics technique, “creates some pretty fertile territory for appeal” if Anthony is convicted.

Dr. Arpad Vass, a top scientist at Oak Ridge National Laboratory in Tennessee, had testified about using a pseudo-scientific practice of capturing the “smell of death.”

Vass and a colleague had used a syringe to extract an air sample from a can holding a carpet sample that had been pulled from Anthony’s Pontiac Sunfire. They then injected the air into an instrument called a gas chromatography/mass spectrometric to identify the substances it contained.

The substances were then compared against a database of more than 400 chemical compounds Vass has identified from the decomposition of bodies at the University of Tennessee Anthropological Research Facility. Donated bodies at the facility, dubbed "The Body Farm," were buried in different depths of soil. Hoods were placed over the locations of the bodies to capture the chemical compounds as they were liberated from the decomposing bodies over four years.

Vass backed up the prosecutors' theory, testifying that he smelled an "overwhelmingly strong" odor of human decomposition in the air sample. He told jurors that his machine found high levels of chemical compounds observed when the body breaks down, such as chloroform, in the sample taken from Anthony's car.

But Anthony's attorneys claim Vass' tests are too experimental and haven't been duplicated anywhere else.

Legal experts say such testimony is problematic for the state.

“You’ve got to be cautious about using stuff like that,” said Deborde. “Just because you have evidence and that evidence seems exciting and dramatic in court, it doesn’t mean you should use it.”

Other evidence used by the prosecutors, like police interrogation recordings, also undermines the state’s case, Napolitano said.

“Those interrogations were made before the police gave her the Miranda warnings,” he said.

Other legal experts, like former prosecutor and veteran criminal defense attorney Mark Eiglarsh, say it’s difficult to prove murder without a known cause of death.

“Yes, there is absolutely ample evidence for these jurors to find that the prosecution met their burden and proved this case beyond a reasonable doubt,” Eiglarsh told FoxNews.com. “The problem is that even after the close of the state’s case, it’s still not completely clear exactly how the child died. That could support a not guilty verdict.”

The Associated Press contributed to this report