A CSI team showed up unexpectedly again Wednesday at the Orlando home of a missing Florida toddler's grandparents, FOX News has learned.

Few other details were immediately available as to why crime scene investigators descended upon the house of Cindy and George Anthony, whose nearly 3-year-old granddaughter Caylee has been missing since mid-June.

It's the fourth time they have been at the home where Caylee Marie Anthony lived with her mom and grandparents. The Orange County Sheriff's Office called Wednesday's visit "routine" and said the girl has not been found.

Detectives didn't talk about the latest search, during which investigators were greeted by Cindy and George Anthony and their son Lee, according to MyFOX Orlando.

Earlier Wednesday, Cindy Anthony said the tot's life may be in danger.

Cindy Anthony told reporters outside her home that her jailed daughter, Casey Marie Anthony, issued the warning about Caylee's safety, according to MyFOX Orlando.

"Casey is telling us Caylee's life is in danger," Cindy Anthony said.

Meanwhile, detectives told FOX News that they were looking into the possibility that Casey Anthony may have impersonated a baby sitter she says took Caylee by signing the sitter's name during a visit to an apartment complex and writing in a visit date within the time frame of the child's disappearance.

On Tuesday, Cindy and George Anthony acknowledged that their daughter stole gas cans from their shed and has lied to them. But they continued to maintain her innocence in Caylee's disappearance.

The Anthonys told FOX News' Greta Van Susteren that they believe 22-year-old Casey when she says she knows who has Caylee but isn't sure where her little girl is. The child turns 3 on Saturday.

The grandmother said Casey has told her what happened to Caylee "in her way," but she couldn't disclose many details.

"I can't reveal that," Cindy Anthony said in an "On the Record" interview that aired Tuesday.

Click here to watch portions of the interview.

When asked about allegations that her daughter is a compulsive liar, she nodded and said that "lying isn't a criminal offense. Lying doesn't mean that you're a murderer."

Van Susteren's "On the Record" segment included a look at the Anthony family's backyard, where investigators and cadaver dogs searched for evidence late last month.

Cindy Anthony said one of the dogs had come upon two "inconsistent" spots — one by the pool and another in Caylee's sandbox — but a second dog didn't detect anything unusual in either place.

Click here to see the tour of the Anthony family's backyard.

George Anthony told Van Susteren he found two cans of gasoline that he had initially reported stolen in the trunk of his daughter's car. Casey Anthony tried, and failed, to prevent her father from going into the vehicle, he said.

On Tuesday the Florida State Attorney's Office filed formal criminal charges against Casey Anthony.

She was charged with one felony and one misdemeanor offense in addition to the child neglect charge she already is facing. She is scheduled to be arraigned Aug. 21 but does not have to appear in court because her attorney submitted a written not guilty plea.

Also Tuesday, test results from DNA samples taken from a car driven by Casey Anthony came in and were turned over to investigators.

The evidence was gathered from the trunk of a vehicle she was using when Caylee vanished in mid-June.

Other DNA samples were taken from the backyard of Anthony's parents' house, where she lived with her little daughter until about the time the girl disappeared. It took Casey Anthony more than a month to report the child missing, which she did on July 15. Caylee was last seen on or around June 15.

Detectives reported smelling a strong odor of human decomposition in the car trunk after cadaver dogs led them there. They said they also found hair samples similar to those belonging to Caylee.

Cindy Anthony said the trunk smelled like a dead body when she called 911 to report her granddaughter missing. She also asked emergency dispatchers to take her daughter into custody.

Authorities from the Florida Department of Law Enforcement were analyzing the DNA results, but the media has been told they won't necessarily be guaranteed immediate or full access to the data.

Orange County Sheriff's Office spokesman Carlos Padilla said police will decide what results to release and when.

Cindy Anthony had planned an early afternoon visit Tuesday with her daughter in prison, but it was canceled — she said out of concern for safety of her granddaughter.

"I feel that it is safer for my granddaughter that I don’t go," Cindy Anthony told reporters Tuesday. "It is a taped interview. ... It is very hard not to see my daughter."

At one point, she lashed out at reporters, saying she tended to be too trusting and she had been "burned by all of you." George Anthony visited his daughter on Sunday, and her brother, Lee Anthony, was planning a 9 a.m. visit on Thursday.

Casey Anthony remains jailed on a $500,000 bond, charged with child neglect, false statements to police and obstructing an investigation. She is considered a person of interest in the case and claims that Caylee was taken by a baby sitter, who also vanished.

Lee Anthony told FOX News on Tuesday that the Anthonys were deliberately withholding the name of Caylee's deceased dad, since his family was never told he had fathered the girl.

"We will never release the name of that person or his family out of respect for that family," Lee Anthony said. "The family was never aware that he was the father."

He also denied reports that he and his sister had been talking in code during jailhouse phone calls.

"We don't have code names or anything like that," Lee Anthony said. "We have no reason to … that sounds like someone playing games and we’re not doing that."

Caylee's mom has promised that her little girl would be home by her third birthday on Aug. 9.

Police say that what little Casey Anthony has told them has proven to be true.

Click here for more on this story from MyFOXOrlando.com.

Click here for a timeline and photos from the Caylee Anthony case.

FOX News' Phil Keating, Ian Rafferty, Catherine Donaldson-Evans and The Associated Press contributed to this report.