What did Casey Anthony’s parents know? How did she get away with so many lies?

The first episode of the three-part series, Casey Anthony: An American Murder Mystery, aired on Investigation Discovery on Sunday. It highlights the incredulous weeks and months following the discovery that Casey Anthony’s two-year-old daughter Caylee had gone missing — and no one in her family reported it.

It started with a 911 call from Casey’s mother, Cindy Anthony, in Orlando, Florida.

“I have someone here that I need to be arrested in my home,” Cindy says in the call. “My daughter.”

The call was about a stolen car. But Cindy Anthony would later reveal that the vehicle smelled like there had been “a dead body in the damn car.”

Casey Anthony tried to stick to her story: That she had last seen little Caylee when she dropped her off with her nanny, Zenaida Gonzalez, who she said was known as “Zanny the Nanny.”

But no such nanny was found. Orlando police asked Casey Anthony to walk them through the day of June 16, the day Caylee went missing. She took them to an apartment where ‘Zanny the Nanny’ purportedly lived. But the apartment was vacant. There was no record of any Zenaida Gonzalez ever living there.

Casey Anthony also insisted, for a while, that she had gone to work as an event planner at Universal Studios the day she went missing. But when police escorted her to her purported place of work, they backed her into a literal corner – at the end of a hallway of offices — and none of them belonged to her.

She turns around and she says.. I don’t really work here.

Cindy and George Anthony both gave interviews for the Investigation Discovery series. Casey Anthony did not. Both her parents are circumspect about what they think happened to their granddaughter – who they both insist was the light of their lives.  So far, they haven’t explained why they didn’t call the police much earlier, why they weren’t alarmed when Caylee suddenly stopped coming home.

“I know in my heart she’s not far,” Casey says in a jailhouse phone call with her parents. “I can feel it.”

A few months later, Caylee Anthony’s skeletal remains were found in a marshy area near the Anthony family home.

Part two of Casey Anthony: An American Murder Mystery will air on Monday at 10 p.m. ET.

Photo: Screenshot/Investigation Discovery