Defense witness refutes evidence in Anthony trial

A forensic expert called by Casey Anthony's defense team is refuting evidence against the Florida mother accused of killing her 2-year-old daughter.

Dr. William Rodriguez is a forensic anthropologist with the U.S. Department of Defense Armed Forces Medical Examiner's Office. In testimony Saturday morning, Rodriguez said it would be impossible to determine the exact position of duct tape on a corpse. Because tape loses its stickiness, it may have shifted, and animals could have come into contact with the body.

The prosecution contends that toddler Caylee Anthony was suffocated by duct tape placed over her nose and mouth.

Her mother is charged with first-degree murder in the 2008 death. Anthony has pleaded not guilty. The defense says the girl drowned in her grandparents' swimming pool.