"She [Casey] never really told [her family] who the father was," Pacheco said. "She did say the dad died in a car accident. And we haven't been able to find out who that was yet."
Pacheco added that Casey had a series of boyfriends after Caylee's birth, but most of them aren't speaking to the press. One man, who says he dated Casey seriously enough that they once considered marriage, spoke with the ABC News affiliate WFTV in Orlando. He asked that his name not be mentioned.
"I just saw her as someone who was trying to juggle being a single mother and, you know, a 22-year-old girl at the same time," he said. "Every time I was around her, Caylee was the center of her attention. Casey was a great parent whenever she was around her."
On Father's Day, June 15, the family took Caylee to visit her great-grandfather at an assisted living facility.
"There was some sort of huge argument Father's Day weekend," said Kathi Belich, a reporter for WFTV. "I am told neighbors heard yelling. There was some sort of big fight."
Two weeks later, on June 30, the family car Casey had been using was found abandoned in front of an Orlando cash advance business and towed away.
When the towing company called Casey's parents, a series of alarms went off. Casey reportedly had told her mother, Cindy, that she was going on a "mini-vacation" in Jacksonville and was spending time with some friends.
Cindy began calling Casey's friends, and her desperation intensified in mid-July when she discovered that her daughter had in fact been staying at an Orlando apartment complex with a boyfriend. Casey told her parents that Caylee had gone missing from her baby sitter's home in June, and that she'd launched her own investigation.
"The grandmother panicked and told her, 'I'm gonna call the cops,'" said Pacheco.
On the 911 tapes, Cindy is heard saying, "I found out my granddaughter has been taken, she has been missing for a month. Her mother finally admitted that she's been missing."
Another call to police on July 15 sent the panic and the stakes even higher.
"I can't find my granddaughter. ... There's something wrong," Cindy said. "I found my daughter's car today and it smelled like there's been a dead body in the damn car."
Cindy later retracted that statement, saying that the smell in the car could have been from garbage, but Casey Anthony became a person of interest in the case.
Authorities have released more than 400 pages of documents, which revealed that Casey told police that she left Caylee with a baby sitter named Zenaida Fernandez Gonzalez, and that both were missing when she returned.
On July 16, 2008, police took Casey on a journey around the city to try to understand her story about where she had left her daughter.
"When [Casey] took them to the apartment [where] she said she had dropped her daughter off, that apartment had been vacant for almost 140 days," said Pacheco. "No one was living there."
Casey then took the police to two other buildings where she said she'd left Caylee in the care of Gonzalez, but the police could find no such woman and they they could not find anyone who knew Casey at Universal Studios, where Casey claimed to work.
Police took Casey into custody and charged her with child endangerment. The arrest affidavit states that she showed no "obvious emotion" over her daughter's disappearance.