ORLANDO, Fla. -- Leonard Padilla revealed he was beginning work to revoke Casey Anthony's $500,000 bond on Thursday morning.

Anthony is the mother of Caylee Anthony, 3, who has been missing since early June. Casey Anthony was released from the Orange County Jail last week on bond and faces child neglect charges over the girl's disappearance.

Casey Anthony left her house about 10 a.m. Thursday for a scheduled meeting with with her attorney, Jose Baez, which could last for as long as six hours.

Anthony is not scheduled to meet with any representatives from the state attorney's office, Public Information Officer Danielle Tavernier said.

Meanwhile, results of DNA tests in connection with the investigation were received by the Orange County Sheriff's Office. They're expected to be shared with the state attorney's office later on Thursday.

Also, an air sample taken from Anthony's car was tested at a University of Tennessee laboratory and tested positive for the smell of human decomposition.

A limited immunity deal for Anthony will expire on Tuesday.

Earlier on Thursday, Caylee's grandfather left his home with an unknown passenger in the car. George Anthony departed from his home just after 6 a.m. He pulled out of his driveway, and another person in the car's front seat could not be identified. He returned shortly before 9 a.m.

Stay with WESH 2 News and WESH.com for further details.

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