By Barbara Liston
ORLANDO, Fla (Reuters) - Was 2-year-old Caylee Anthony's body ever in her mother's car trunk?
Prosecutors in the first-degree murder trial of Casey Anthony are expected to call experts to testify that analysis on air from the 25-year-old Florida mother's trunk was consistent with human decomposition.
But in an Orlando courtroom on Thursday, Casey Anthony's father testified that he did not smell human decay when his daughter opened her car trunk in his presence eight days after Caylee died in June 2008.
"The only smell I had was the smell of gas," George Anthony said.
Casey's then-boyfriend Tony Lazzaro testified Wednesday and again Thursday that he also had noticed only a gas smell coming from the trunk.
In both instances, Casey had opened her car trunk out of each man's clear view to put in or take out two used gas cans.
Defense attorneys unsuccessfully fought to keep the unusual air analysis out of the courtroom on grounds that it is unproven science, and legal experts have said the issue is a sure-fire point for appeal should Casey be found guilty.
Casey Anthony faces the death penalty if convicted of charges that she killed her daughter on June 16, 2008, by wrapping the toddler's face and head three times with duct tape and dumping her body in woods near the Anthony home.
The child was not reported missing until July 15, 2008. After finding Casey's car in an impound lot, Caylee's grandmother, Cindy Anthony, called 911 and famously told the dispatcher that the trunk smelled like a dead body.
The defense contends that George Anthony found Caylee drowned in the family's backyard pool on June 16 but no one reported the accident.
The defense is trying to raise suspicion about George Anthony. In opening statements, defense lawyer Jose Baez accused George of sexually molesting Casey starting at age 8, a charge the father denied Tuesday from the witness stand.
Back on the stand Thursday, George Anthony was grilled by Baez about how and when a piece of duct tape appeared on a gas can he kept in a shed, one of the same cans that had been in Casey's trunk.
The tape is important: It is the same distinctive brand that was found wrapped around Caylee's skull when her remains were located on December 11, 2008.
For prosecutors, the tape provides a link between Caylee's killer and the Anthony home where Casey and Caylee lived with George and Cindy.
George testified that he believed Casey had lost a small cap that covered a vent hole and that he probably covered it with duct tape when she returned the can on June 24 to keep fumes from escaping.
Baez pressed George about whether he knew at the time he placed the tape on the can that the tape was a "significant issue."
"On June 24th, I did not know a few weeks later that my granddaughter would be reported missing," George said.
Spectators have continued to arrive before dawn to nab a seat at the trial, which has drawn national attention and is expected to last up to eight weeks.
On Thursday, the 17 jurors sent notes to the judge asking him to identify who among them made up the dozen jurors who will decide the case and whether the alternates could go home after all the evidence had been presented.
Judge Belvin Perry declined to answer.
Jurors also asked for pretzels in the jury room, to watch a televised hockey game on their time off, and whether they can write in personal journals.
(Editing by Colleen Jenkins and Greg McCune)