(CNN) - On the third anniversary of the day 2-year-old Caylee Anthony was last seen alive, attorneys for her suspected killer - her mother, Casey Anthony - kicked off their defense Thursday, presenting testimony about DNA and forensic procedures.

Testing found no blood on any of Anthony's clothes, in her car trunk or in the interior of the car, according to FBI examiner Heather Seubert and Orange County, Florida, Sheriff's Office crime scene technician Gerardo Bloise.

The two were the first witnesses called by Anthony's defense on a day that saw several heated exchanges between the prosecution and the defense.

Prosecutors allege that Anthony, 25, killed Caylee in 2008 by using chloroform on her and putting duct tape over her nose and mouth. They allege she then put the little girl's body in black garbage bags and stored it in her trunk before dumping it in woods near her home.

Caylee's skeletal remains were found December 11, 2008. Although she was last seen June 16 of that year, her disappearance was not reported until July 15, after Anthony's mother demanded answers from her daughter about Caylee's whereabouts.

Anthony faces seven counts in Caylee's death, including first-degree murder, aggravated child abuse and misleading investigators. If convicted, she could face the death penalty. She has pleaded not guilty, and her defense attorney Jose Baez has said that when all the facts are known, his client's innocence will become clear.

The defense has said Caylee was not killed but rather drowned in the family pool June 16. Baez told jurors in his opening statements that Anthony and her father, George Anthony, panicked when they discovered the body and covered up her death. George Anthony rejected that scenario in his testimony the first week of the trial.