Contra Costa County Capt. Daniel Terry told ABCNews.com today that authorities from the county's multi-agency task force had visited Garrido as part of routine compliance check, but did not offer any details regarding frequency or how thoroughly the property was checked.
The San Francisco Chronicle reported that the task force visited the Garrido's Antioch home last summer.
"There were zero signs of kids living there," Antioch Police St. Diane Aguinaga told the Chronicle, adding that authorities looked in the back but saw only a porch and shed.
El Dorado County Undersheriff Fred Kollar on Thursday confirmed that a parole officer had looked in the back, but said the secret yard was hidden by a six foot fence and tall trees. The entrance was concealed by a tarp that had to be pulled aside. If a person didn't know the yard existed, Kollar said, there would be no way to know there was an entrance.
"The way the house is set up, the way the back yard is set up, you could walk through the back yard, walk through the house and never know that there was another set of living circumstances in that back yard," the sheriff said.
And the view by neighbors was also screened. "The tents and outbuildings were strategically placed to inhibit outside viewing," Kollar said.
Next-door neighbor Helen Boyer, who Thursday described the Garridos as "nice people," told ABCNews.com today that she was "numb" after learning about the abuse allegedly at the hands of people she'd known for more than 10 years.
"I feel terrible," she said. "When they mentioned the house of horror, it upset us really bad."
Boyer said she had seen three young girls at the house, who she now believes to be Jaycee and her 11-and 15-year-old daughters, but never thought anything was amiss.
She had known for a long time that Garrido was a registered sex offender, but didn't think to call authorities "because it was supposedly Nancy's friend's kids."
Boyer was also shocked to learn about the complicated backyard labyrinth, telling ABCNews.com that it's not visible from her yard even now that she knows about it.
""We have real big backyards and there would be no occasion for me to even look back there. There's a high fence," she said. "If I stood on something I would look over there, but you wouldn't be able to see all the tents."
Another neighbor, Diane Doty, told the Associated Press she could see the tents and often heard children playing in the backyard, the corner of which abuts her own backyard. She said she even suspected the children lived in the tents, but her husband said she should leave the family alone.
Jaycee's family is still reeling from the little girl who disappeared in 1991 is alive, although has had to endure brutal conditions.
Carl Probyn, who had long since given up hope of finding his stepdaughter alive, told "Good Morning America" today that getting reacquainted is going to be a challenge for everyone. Jaycee is largely uneducated, having spent the majority of her life relegated to the Garrido's backyard.
"It's pretty sick," Probyn said. "I feel sorry for Jaycee going through this. The way he's had her locked up in the backyard for basically 18 years."
Jaycee's two daughters with her accused kidnapper, 11 and 15, have never been to school or seen a doctor.