"I don't know if she was brainwashed, I don't know if she was walking around on the street, I don't know if she was locked up under key for 18 years, I have no idea," he said.
Police have admitted that they missed an opportunity to uncover what was happening at Mr Garrido's home in November 2006, when a neighbour alerted them to suspicious behaviour there.
"The caller said Garrido was psychotic and had a sexual addiction," Sheriff Warren Rupf told reporters.
But the investigating police officer only spoke to Mr Garrido and did not enter his property to carry out a search.
"I'm first in line to offer organisational criticism and to offer my apologies to the victims and accept responsibility for having missed an earlier opportunity," said Sheriff Rupf.
'A disgusting thing'
Jaycee's stepfather gives details to ABC's Good Morning America
Fred Kollar, undersheriff in El Dorado County where South Lake Tahoe is located, described finding a makeshift compound in the backyard consisting of sheds, tents and outbuildings.
The true identity of the backyard's inhabitants only emerged after Mr Garrido was called in along with his "family" for a parole office hearing on Wednesday.
Suspicions had been aroused when Mr Garrido, who has a printing business, was seen acting suspiciously towards the children as he tried to enter the University of California, Berkeley, campus to hand out religious literature.
Diane Doty, a neighbour, has said she often heard children playing in the backyard.
"I asked my husband, 'Why is he [Garrido] living in tents?'" she said on Thursday.
"And he said, 'Maybe that is how they like to live.'"
The alleged abductor has himself told a US TV channel that his story was "heart-warming".
"It's a disgusting thing that took place with me at the beginning, but I turned my life completely around," Mr Garrido told KCRA television from El Dorado County jail.
Court records show that Mr Garrido was convicted of kidnapping and raping a 25-year-old woman in South Lake Tahoe in 1976.
Layout of the back garden where Jaycee Lee Dugard is said to have lived
Unless Dugard was kept under lock and key for the entire 18 years of her captivity, over the next few days, certainly there will be an abundance of pieces about Stockholm syndrome and wondering why she didn't ask for help before... If Dugard's captors gave her any freedom, locals will start piping up about how she went to the grocery store or to the park, suggesting that she could have fled at any time.
Over the last 18 years I have often thought about what happened to Jaycee. Every time there was a news report about the discovery of bones in California, I would follow up to see if it was the remains of Jaycee. It never was. Over 18 years my mind wandered back to me sitting in Jaycee's bedroom with Terry, how neat and tidy it was, ready for her return. I hadn't thought about Jaycee in a while, until today.
Though the investigation is now ongoing, perhaps more details will emerge [about Nancy Garrido's] role in this 18-year saga. Was it fear that kept Nancy silent? Or does this just go to show how some women can overlook the monster in their husbands?
The fact that various acquaintances thought Garrido was crazy and actually saw Dugard and her daughters reveals how willing we sometimes are to ignore the strange behavior of others, and how this willingness can sometimes allow criminals to operate with impunity for years.
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