He said: "Phillip Garrido had access to that property. He used that property and it looks like he lived on that property in a shed" before current occupant Damon Robinson moved in in 2006.
Mr Robinson had earlier told the Associated Press news agency that Mr Garrido used to act as a caretaker for the property until 2006. Neighbours told AP he used to visit and help out the previous elderly resident.
Mr Lee stressed that Mr Robinson had fully cooperated and was neither a suspect nor a person of interest.
"There are no other suspect leads in this case," Mr Lee said.
He said dogs were being used to search the properties, including those trained to look for bodies.
However, he said it was too early to say if there were any links to other "open cases".
Media have said police have been searching for clues to a number of prostitute murders in the 1990s. Several bodies in the unsolved murders were dumped near an industrial park where Mr Garrido worked.
Jimmy Lee, County Sheriff's spokesman
Mr Lee said officials expected to finish searching the two properties by Sunday evening local time.
The spokesman said he had no information on the progress of Ms Dugard and her children.
They are said to be staying at a motel near San Francisco after being reunited with Ms Dugard's mother, Terri Probyn.
Held without bail
Ms Dugard is believed to have been living in tents and sheds in the backyard of the Garridos' Antioch home for 18 years.
Her identity was rediscovered last week, after Mr Garrido was ordered to a parole meeting by police officers whose suspicions had been aroused by the behaviour of two girls with him.
No pictures have yet been released of Ms Dugard as she looks today
The two officers, Lisa Campbell and Ally Jacobs, met Mr Garrido on Tuesday as he sought to hold a religious meeting on the grounds of the University of California at Berkeley, where the officers work.
Officer Jacobs said something about the girls, aged 11 and 15, alarmed them.
"I think Lisa asked, 'do you guys go to school?' and they both, like robots, [said] 'we're home schooled'."
The officer said they noticed the girls were "extremely pale in comparison" to Mr Garrido, and had "penetratingly blue eyes and I just got a weird uneasy feeling".
Police have apologised for missing an opportunity in November 2006 to find Ms Dugard.
An officer visited the Garrido home when a neighbour - reportedly the then-girlfriend of Mr Robinson - alerted them to suspicious behaviour there.
But the officer only spoke to Mr Garrido and did not enter his property to carry out a search
Mr and Mrs Garrido are being held without bail and a further court hearing has been scheduled for 14 September.
Layout of the back garden where Jaycee Lee Dugard is said to have lived
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.