A hearing was held Friday to determine whether a jury should hear that a heart sticker was placed on a piece of duct tape found on Caylee Anthony's skull.

Casey Anthony's defense team wants to prevent that information from reaching trial. They argue there is no credible evidence that any heart sticker was ever on the duct tape.

The state points to an FBI lab analyst who said she saw a heart-shaped outline on the tape, but she said it disappeared before she could photograph it. She never said it came from a sticker and no such sticker was found with Caylee's remains.

The defense has called it the "phantom sticker."

One sticker was found attached to cardboard found 30 to 40 feet away from the skull, which was found in a wooded area in east Orange County near the Anthony family home in December 2008, five months after 2-year-old Caylee was reported missing.

A slew of heart stickers were found during a search of Anthony's parents' house, but the sticker found on the cardboard does not match in shape or size to any of the heart stickers found in the home.

The defense will try to keep several other things out of trial, as well.

It wants no mention of a stain found in Anthony's trunk, which an FBI agent said resembled the imprint of a child curled in the fetal position. In addition, the defense wants to bar testimony from K-9 handlers who said their dogs indicated human remains had been in the trunk of Anthony's car and her parents' back yard.

Judge Belvin Perry's ruling on these issues could prove crucial in Anthony's first-degree murder trial, which is scheduled to begin May 9. Prosecutors are seeking the death penalty against Anthony in her daughter's death.