Detectives spent Friday digging through the backyard of the grandparents of a Florida toddler who's been missing more than a month.
Orange County Sheriff's authorities combed the Orlando yard of 2-year-old Caylee Marie Anthony's grandparents Cindy and George Anthony in the hopes of finding clues in the child's disappearance.
Cadaver dogs were at the scene, and several items were removed from the home, which became the focus of the investigation after a neighbor said the child's mother, Casey Marie Anthony, had borrowed a shovel about a month ago. That shovel has reportedly been taken by police as evidence.
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Casey Anthony, 22, has been in custody since Wednesday, when she finally reported the child missing. The little girl lived in the house with her mother and grandparents until June 9, when Casey said she disappeared.
"This is difficult, tedious work," sheriff's Sgt. John Allen, who oversees the department's child abuse and missing persons division, told reporters during a press briefing Friday. "Just because we’re here with cadaver dogs doesn’t mean we’re giving up hope that Caylee is alive."
Allen said they haven't found signs of the girl in the yard but it is only "one of several places we're looking." He wouldn't elaborate.
Caylee's grandparents had been "very cooperative" in the investigation, according to Allen; the sheriff's office said the search of their property in no way implicated them in the case.
"It's very clear to us that they want their granddaughter back," Allen said.
The hunt for evidence began Thursday night but stopped when darkness fell and resumed Friday morning. Detectives found "abnormalities" in the dirt that caused them to be suspicious, according to MyFOX Orlando.
Described by friends as a "habitual" and "compulsive" liar, Casey Anthony told investigators that she dropped Caylee off with a friend on June 9. Authorities have been unable to locate that woman, or verify anything else Anthony told them.
The FBI told FOXNews.com that the bureau is aware of the case, but isn't playing a part in the probe.
"We're definitely aware of it and monitoring the situation, but that's the extent of our involvement," said Special Agent Dave Couvertier, a spokesman for the Orlando and Tampa FBI.
Orange County Sheriff's Capt. Angelo Nieves said the grandparents' property on Hopespring Drive is central to the investigation, but didn't provide further details, according to the Orlando Sentinel.
Allen said sheriffs spent several hours with Casey Anthony after her arrest, but procedural regulations have barred them from interviewing her further in jail without her attorney.
Neighbor Diana Centeno, whose children have played with Caylee in the past, called the situation "scary," according to the Sentinel. She said she hoped Casey Anthony didn't have anything to do with the toddler's disappearance.
Anthony was arrested Wednesday on charges of child neglect and providing false information to law enforcement. She showed no emotion Thursday as she was ordered held without bond at the Orange County Jail.
The judge scolded the mother, saying she had "no regret or concern for her actions," the Sentinel reported.
"You left your 2-year-old child with a person who does not exist at an apartment you cannot identify and you lied to your parents about your child's whereabouts," said Judge John Jordan. "You cared so little about your child."
He ordered a mental health evaluation be done on Anthony, according to the newspaper.
The Orange County Sheriff's Department told FOXNews.com that they have no reason to believe the toddler is dead.
"[We are] still operating under the hope she is going to turn up alive," Deputy Sheriff Carlos Padilla said. "[But] we are no closer today than we were yesterday."
Padilla said Anthony claims the child's father is not alive — something authorities are still looking into.
Investigators said their job has been made more difficult because Anthony continues to spin stories that aren't true.
"Based on the repetitive lies that the defendant has told, we do not know with whom the child is or even if the child is alive," sheriff's Cpl. Yuri Melich wrote in the arrest affidavit, according to the Sentinel. "It should be noted that at no time during any of the above interviews did the defendant show any obvious emotion as to the loss of her child."
Anthony told her mother that she was being sent to Tampa for work and would be back in a few days, but later changed her story and said she was going on a "mini-vacation," according to the Sentinel.
"I had no reason to believe they weren't where they were supposed to be," the newspaper quoted Cindy Anthony as saying. "I don't know why she fabricated this."
It was not clear why Casey Anthony never reported the child missing. The girl's grandparents decided to file the report on Tuesday after learning their daughter's car had been towed from a location that was nowhere near where she claimed to be staying.
"I’ve had the feeling the past couple of weeks that Casey's been holding back," Cindy Anthony told MyFOX Orlando. "I’ve been asking to speak with my granddaughter and she’s been making excuses that I can't talk to her because she’s with someone else or she’s swimming or napping."
Casey Anthony told police that her daughter wasn't at the baby sitter's house when she went to pick the child up, so she started to do her own investigation.
She went to clubs that the baby sitter frequented and identified her as Zenaida Gonzalez, police said. But when detectives went to the apartment Anthony said belonged to the alleged baby sitter, they learned it had been vacant for almost five months, the newspaper reported.
Once detectives caught up with Gonzalez and showed her pictures of both Anthony and Caylee, Gonzalez said she didn't recognize them.
Anthony also told authorities that she worked at Universal Studios, and gave names of people who could vouch for her, according to the Sentinel. But officials later learned she was never employed at the theme park — and neither were the people she mentioned.
George Anthony said his daughter is a good mom and would not hurt his grandchild.
"My daughter is a fantastic mother," he told FOX News. "Our granddaughter's in capable hands. She was nurturing, she always did the right thing. ... I never once saw my daughter raise her voice."
Allen said police want to keep the case out in the public, and are following up on numerous leads that have come in because of the media coverage.
The Orange County Sheriff's Office is asking anyone who has seen Caylee to call the crime line at 1-800-423-TIPS.
FOX News' Catherine Donaldson-Evans, Michelle Maskaly and The Associated Press contributed to this report.