ORLANDO, Fla. – The defense concentrated on the reliability of the prosecution's forensic evidence Thursday when it called its first witnesses in the murder trial of Casey Anthony, the Florida woman accused of killing her 2-year-old daughter.
An FBI technician testified that the duct tape found attached to the decomposed skull of toddler Caylee Anthony was contaminated during testing by another technician.
Heather Seubert, who examined the tape at an FBI lab, told jurors that DNA on the tape did not match the victim, her mother Casey or her grandparents. Instead, it matched another forensic examiner who analyzed the duct tape.
The child's skeletal remains were found in a wooded area near the family's home in December 2008.
FBI lab technician Lorie Gottesman later testified that it was her DNA found on the duct tape. Gottesman, who is a forensic document examiner, said she wore gloves during her examination.
"I have no idea how it happened or when," she told jurors.
Casey Anthony's defense team began presenting its case on the third anniversary of the last time Caylee Anthony was seen alive.
The 25-year-old mother is charged with first-degree murder Caylee's summer 2008 death and has pleaded not guilty. The state contends the child was suffocated by three pieces of duct tape being applied to her face. The defense said in its opening statement that she drowned in her grandparents' above-ground swimming pool.
If convicted, Anthony faces a death sentence.
Defense attorney Jose Baez also got Gottesman to detail for jurors her inability to locate any traces of the outline of a heart-shaped sticker on the exterior of the duct tape, despite subjecting it to advanced video enhancement.
A FBI physical scientist testified during the prosecution's case that she noticed the outline of a heart on one of the three pieces while examining it under ultra-violet lighting. There were no pictures taken of what she saw, though. After subjecting the tape to chemicals during fingerprint testing, it was no longer present.
Later, Seubert noted several items of evidence submitted by the prosecution that she tested for the presence of unknown DNA, blood and semen. Those items included pieces of a spare tire cover from the trunk of Casey Anthony's car, a shovel she borrowed from her parents' neighbor, several items of clothing from Casey's bedroom and a shovel found with her daughter's remains.
Seubert said a few had stains or other areas of interest on them, but none of them showed any testable signs of DNA, blood or semen.
Also, a pair of shorts and remnants of a shirt that were found at the site of Caylee Anthony's remains also didn't show a confirmable presence of blood. DNA could also not be obtained from the items.
Under cross-examination, prosecutor Jeff Ashton tried to discredit the importance of DNA not being found on the items.
"If the method of killing someone does not involve bloodshed, then the absence of blood doesn't matter, does it?" Ashton asked.
"Correct," Seubert responded.
Seubert also acknowledged that pulling DNA off the items was affected by other variables and that signs of human decomposition — like the prosecution contends was present in Casey Anthony's car trunk — are also affected.
"The likelihood of obtaining DNA result does diminish as the body starts to breakdown," Seubert said.
The most contentious incident of the morning came just before the lunch break when Baez asked Seubert whether she was asked to conduct paternity tests for Caylee Anthony from DNA swabs of the child's own grandfather and uncle.
The defense has claimed that Casey Anthony was abused in the past by both her father, George, and her brother, Lee. George Anthony denied those claims in earlier testimony. Lee Anthony has yet to be asked about it on the witness stand.
"Were you asked to conduct paternity testing for Lee Anthony as a potential father for Caylee Anthony?" Baez asked.
Ashton immediately objected and Judge Belvin Perry dismissed the jury for lunch.
After they left, Ashton argued that Baez didn't have "a good-faith basis" to ask the question and asked that it be stricken.
The judge made a short inquiry of Seubert, asking her what she was asked to test for by investigators. She had references in her notes that other investigators wanted to know if samples from George and Lee Anthony were candidates for possible paternity testing, but that her lab wouldn't have conducted an actual statistical paternity test. Both Lee and George Anthony were later excluded by additional paterty testing.
Ashton then asked Perry to strike the question from the record. After lunch, the judge decided that the reference to Seubert being "asked to conduct" a paternity test would be removed from Baez's question but not the whole query.
Associated Press writer Harry Weber contributed to this report.