ANTIOCH, California (CNN) -- Phillip Garrido and his wife, Nancy, will face 29 felony counts after being accused of kidnapping Jaycee Lee Dugard when she was 11 and keeping her in their backyard since 1991, the district attorney of El Dorado County, California, said Friday.
Phillip Garrido, a registered sex offender, was arraigned in California on Friday.
The Garridos are each facing charges of kidnapping someone under 14 years of age, kidnapping for sexual purposes, forcible rape and forcible lewd acts on a child.
The maximum penalty for both defendants would be life imprisonment.
Authorities are looking into Garrido's possible connection to other crimes. Hear interview with Garrido »
A search warrant was issued for Garrido's home in connection with killings that occurred in the 1990s, a spokesman for the Contra Costa Sheriff's Department said Friday. Pittsburg, California, police obtained the search warrant, said the spokesman, Jimmy Lee.
Earlier Friday, a California sheriff also admitted that his organization "missed an opportunity" nearly three years ago to find Dugard.
Someone called 911 on November 30, 2006, to say that a woman and young children were living in tents in the backyard of Phillip Garrido, said Sheriff Warren E. Rupf of Contra Costa County, California, on Friday.
"This is not an acceptable outcome," he said. Watch Rupf talk about the 'missed opportunity' »
The responding sheriff's deputy spoke with Garrido, a registered sex offender, in the front yard of his house.
"None of us, particularly law enforcement, should believe a word that one of these animals utters," Rupf said when asked about the lessons learned from the missed opportunity. "If there's a sophistication [about sex offenders] in any regard, it's in misrepresenting who they are and what motivates them.
"We took things he said obviously at face value and did not properly brand him."
Rupf also said that "to the best of his knowledge," the deputy didn't know that Garrido was a sex offender.
The deputy determined that no crime had been committed even though he did not enter or ask to enter the backyard, the sheriff said.
"We should have been more inquisitive, more curious, and turned over a rock or two," the sheriff said. "We missed an opportunity to bring earlier closure to this situation."
Dugard lived for 18 years in a shed and other outbuildings behind her abductor's house, where she gave birth to two girls whom he fathered; the girls are now 11 and 15, police said.
CNN policy is not to publish the names of victims when there are allegations of sexual assault. In this case, Dugard has been the subject of a 20-year public search and her image and name have been widely disseminated, making protection of her identity virtually impossible.
Dugard was kidnapped in 1991 as her stepfather watched, helpless, in front of her house in South Lake Tahoe, California. Learn about some missing children who have been found alive »
Investigators arrested Garrido on charges of kidnapping and abusing her after police discovered Dugard on Wednesday.
"The last 18 years have been rough, but the last two days have been pretty good," her stepfather, Carl Probyn, told CNN's "American Morning" on Friday. Watch Probyn describe getting the news »
Phillip Garrido, 58, and 54-year-old Nancy Garrido were arraigned Friday in Placerville Superior Court in Placerville, California. They pleaded not guilty Friday.
During their time living in Garrido's backyard, Dugard and her two children apparently rarely ventured out of their compound, investigators said.
Dugard "was in good health, but living in a backyard for the past 18 years does take its toll," El Dorado County Undersheriff Fred Kollar said.
He described her as "relatively cooperative, relatively forthcoming" in discussions with detectives. She was "in relatively good condition," neither obviously abused nor malnourished, he added. "There are no known attempts by her to outreach to anybody."
The children didn't go to school or to the doctor's office. Now they and their mother are being thrust into a strange new world.
On Friday, Dugard began the long process of reuniting with her family. Watch about recovering from captivity »
Terry Probyn, who is separated from Carl, spoke with her daughter Thursday and learned that she had two daughters of her own, he said.
Carl Probyn said he expects Dugard and her two children to come back to Southern California, since "that's where we all live."
Garrido apparently maintained a blog in which he claimed to control sound with his mind. The blog now has numerous profanity-laced responses from people outraged over his alleged actions.
In a rambling telephone interview from jail, Garrido told CNN affiliate KCRA of Sacramento that he was relieved at being caught.
"I feel much better now," he said. "This is a process that needed to take place."
The investigation went years without apparent progress until Tuesday, when Garrido showed up on the campus of the University of California at Berkeley with his two daughters and tried to get permission to hand out literature and speak, Kollar said. He did not know the subject of either the literature or the planned talk.
Police officers "thought the interaction between the older male and the two young females was rather suspicious," so they confronted them and performed a background check on him, Kollar said.
That check revealed that Garrido was on federal parole for a 1971 conviction for rape and kidnapping, for which he had served time in the federal penitentiary at Leavenworth, Kansas.
The two female police officers contacted Garrido's parole officer, who requested that he appear Wednesday at the parole office. Watch police talk about why they arrested Garrido »
Garrido did just that, accompanied by his wife "and a female named Allissa," Kollar said.
The presence of Allissa and the two children surprised the parole officer, who had never seen them during visits to Garrido's house, Kollar said.
"Ultimately, Allissa was identified as Dugard," Kollar said.
Scott Kernan, undersecretary of the California Department of Corrections and Rehabilitation, said Garrido admitted having abducted Dugard.
Dugard's presence behind Garrido's home since apparently went unnoticed in the neighborhood, where homes on one-fourth to one-half-acre lots typically sell for less than $200,000, said Kathy Russo, whose father has lived two houses away from the Garridos for 33 years. Watch aerial view of backyard compound »
"My dad said he never saw a young woman," Russo said, adding that her 94-year-old father considered Garrido to be a "kind of strange, reclusive, kind of an angry kind of guy."
She said the one-story house's backyard was obscured by trees and ringed by a wooden fence.
In his jailhouse interview, Garrido told KCRA that he could not go into detail about why he chose to abduct Dugard. "I haven't talked to a lawyer yet, so I can't do that," he said.
But Garrido said he had "completely turned my life around" in the past several years. "You're going to find the most powerful story coming from the witness, from the victim," he promised. "If you take this a step at a time, you're going to fall over backward, and in the end, you're going to find the most powerful, heartwarming story."
He added, "Wait till you hear the story of what took place at this house. You're going to be absolutely impressed. It's a disgusting thing that took place with me in the beginning, but I turned my life completely around."
Describing his two daughters, he said, "Those two girls slept in my arms every single night from birth; I never kissed them."
In a later comment, he said that, from the time the youngest was born, "everything turned around."
CNN's Taylor Gandossy, Tom Watkins, Stan Wilson and Mallory Simon contributed to this report.