Casey Anthony Trial: Day 27 - Hair Test revisited by FBI [PHOTOS]

Casey Anthony murder trial has entered Day 27 on June 23.

On Wednesday, an attorney for Casey Anthony's parents told CNN that the Anthonys do not believe Casey is innocent. George and Cindy Anthony, however, do not want their daughter to receive the death penalty for the killing, said lawyer Mark Lippman.

On Thursday, defense attorneys have called an FBI expert on hair and fiber to the witness stand, as they try to poke holes in some of the prosecution's forensics evidence.

FBI technitian Stephen Shaw, who analyzed hair found in Casey's car truck, took the witness.

Caylee's remains were found in a wooded area not too far from the Anthonys' home in December 2008.

On June 13, Shaw had testified for jurors and explained his analysis of the hair found in Casey's trunk as well as the hair samples taken from Caylee's skull. Shaw found evidence of decomposition on the hairs, and that a higher level of decomposition was found on the hairs taken from the child's skull than the trunk.

Today, Shaw explained that conditions were different from Florida's when he collected test hair samples, and the conditions under which Shaw tested the hair strands were much colder than temperatures found in Florida. Shaw said that according to his study, which placed a hair in trunk for seven months, there were no changes in hairs kept in the dark.

Anthony's defense attorney Jose Baez asked whether the studies needed to be more advanced and gain more samples before proving their reliabilities, as this type of science was quite new in a court of law.

With the defense case entering its seventh day, the defense's first witness on Thursday was Susan Mears, a crime scene investigator with the Orange County Sheriff's Office. She brought items taken from the wooded area, a Gatorade bottle, a syringe and a Disney Bag, which were introduced into evidence.

Forensic chemist Michael Sigman, one of five forensic witnesses to testify on Wednesday, had collected and tested air samples from the trunk of Casey Anthony's car in July 2008. Based on his analysis, Sigman couldn't be sure there was a body inside of it.

Charged with first-degree murder of her 2-year-old daughter Caylee Marie Anthony, whose body was found in November 2008, Casey Anthony has maintained her innocence of all charges.

The prosecution claims Casey murdered her daughter by suffocation and kept the corpse several days, then dumped the body in the woods near her parents' home.

Casey Anthony could face death penalty if she is found guilty of murdering her daughter.