As Casey Anthony faces first-degree murder charges in the disappearance of her 3-year-old daughter, Caylee, Local 6 News investigative reporter Tony Pipitone has sifted through thousands of documents, looking into whether the girl died on June 16, the key date in the case.

Pipitone said to understand why investigators believe Caylee is dead starts early in the morning of June 16, when Anthony called her boyfriend, Tony Lazzaro, from her parents' house.

The 80-minute phone call ended at 1:05 a.m., and Anthony then had a conversation via text messages with Lazzaro until Lazzaro called her at 3:08 a.m.

It is not known what was discussed, but less than 10 hours later, Caylee, who was 2 at that time, was seen for the last time by her grandfather, George Anthony, Pipitone reported.

"Ten minutes to 1 (o'clock) that afternoon on the 16th is when I actually saw Casey and Caylee together -- both leaving with backpacks -- and my daughter said she was going to work, and she was taking Caylee to the nanny, to the baby sitter," George Anthony said.

Just before 8 p.m., seven hours after Caylee was last seen alive, Casey Anthony and Lazzaro are seen on surveillance video visiting the Blockbuster store near his apartment on University Boulevard. Caylee is not in the video.

Lazzaro told Local 6 News that he had not seen Caylee at that point for two weeks.

The video is one reason investigators believe June 16 may have been the day Caylee died, Pipitone reported.

"What happened in the next hours is even more intriguing. Tony (Lazzaro) and Casey rented two movies for that night. One one of them (was) "Untraceable," which contains a graphic scene that is even more chilling when you consider where Caylee's body may have been," Pipitone said. "The movie shows an FBI agent being pursued by a sadistic cyber-stalker who pops the trunk of a car and is overcome by the smell of a fly-infested, rotting corpse left by the killer in the trunk of the car."

Investigators believe Caylee's body was left in the trunk of her mother's car, where it decomposed, emitting an odor that Casey Anthony's mother, Cindy Anthony, identified, Pipitone reported.

"It smells like there's been a damn dead body in the car," Cindy Anthony said in a 911 call.

"Whether the movie scene is a clue to what Casey might have already done or was about to do -- or even where Caylee may have been on the same night they rented that movie -- only Casey can answer that, and she's not talking," Pipitone said.

Pipitone said he will continue to investigate the timeline into the case using cell phone records that show who Casey Anthony was talking to or texting.

Watch Local 6 News for more on this story.

Casey's Parents Speak Out

George and Cindy Anthony have maintained that they believe Caylee is still alive, saying cell phone records and recently released forensic results do not prove that Caylee is dead.

The Anthonys spoke to Local 6 News reporter Adam Longo, the first time they've talked publicly since the forensic results were released.

"George and I don't believe that Caylee is in the woods or out there," Cindy Anthony said. "We believe someone has her, and that she's alive."

The Anthonys have a private investigator looking into tips that continue to come in.

"Exact spot? We're getting close," Cindy Anthony said. "We feel we're on the right track. We believe -- and we have from Day 1 -- that Caylee has not stayed in the same place for very long. We believe that she's been moved several times."

Cindy Anthony said the Orange County Sheriff's Office has spent more time building a case against Casey Anthony than looking for Caylee.

"I feel like we've lost four months of precious time (to) follow up on looking for her alive," Cindy Anthony said. "I'm angry, and for them to pull that and this is all they've got. This is ridiculous."

"There's a lot more to this story than you guys could ever imagine, and it's all going to come out," George Anthony said.

"There's only one reason why my daughter would keep her mouth shut and why she would sacrifice going to prison the rest of her life -- to protect this child," Cindy Anthony said.

Physical Contact In Prison