Updated

A person of interest sought in connection with Jessica Lunsford's (search) disappearance is a male registered sex offender who was last seen in Savannah, Ga., according to police.

Law enforcement became interested in talking to John Evander Couey (search), who goes by the nickname of "Johnny," while they were trying to contact every registered sex offender who lived near Jessica's home.

Detectives discovered that Couey, 46, was no longer living at his listed address and hadn't notified authorities of his move, even though such notification was required by law.

From interviewing relatives, investigators found out that Couey had traveled to Savannah, Ga. He had lived about two miles north of Jessica's home but sometimes stayed with relatives who live within "eyeshot" of her house, Citrus County Sheriff Jeff Dawsy said.

Couey has an extensive criminal record. In the past he was arrested for burglary, carrying a concealed weapon, indecent exposure, disorderly conduct and larceny. In 1991, he was arrested in Kissimmee on a charge of fondling a child under age 16. In 1978, during a burglary of an occupied residence, he was accused of grabbing a girl in her bedroom, placing his hand over her mouth and kissing her, Dawsy said.

On Sunday, police in Georgia tracked down Couey at a Salvation Army shelter at the request of Citrus County officials. Couey then agreed to go to police headquarters, where he was interviewed, Savannah-Chatham County Police Chief Dan Flynn said.

But Flynn said by the time Citrus County officials asked them to talk to Couey again Monday, he couldn't be located. Two Citrus County investigators have joined the search for Couey in Savannah, he said.

A warrant had been issued for Couey's arrest on a probation violation for marijuana possession, but because it was only a local warrant Savannah authorities had to release him following the interview. That warrant has since been upgraded, and another warrant has been added because of Couey's failure to notify authorities he had moved, authorities said.

"He is getting more and more interesting to us as time as goes on," Dawsy said.

The child's father, Mark Lunsford, earlier said sheriff's detectives told him little about their investigation and nothing about the man they are seeking, who officials had said knew Jessica from "family, social, school, church" circles.

Meanwhile, Jessica's father and grandmother said Wednesday they had faith Jessica would be found safe.

"I truly believe my daughter is alive and is coming home," Mark Lunsford told reporters outside the family's home.

Ruth Lunsford, the girl's grandmother, had a message for the girl: "I know that Jessie's coming home and I can say to you Jessie is 'pray, pray baby ... you're coming home.'"

A statement issued earlier Tuesday by Dawsy said that "red flags" were raised in an FBI polygraph test given March 4 to Ruth Lunsford regarding two of her responses. But investigators were unable to determine what, if anything, she might know about Jessica's disappearance, the sheriff said.

"I'm not sure it wasn't stress-induced," Dawsy said. "We have totally not been able to rectify one of the answers she gave or why we got this type of response."

He declined to elaborate.

Ruth Lunsford, 73, said investigators have told the family nothing.

"I have no idea what they are talking about. I'm sorry, I'm under a lot of stress," she said.

No concerns were raised in polygraph tests given to the girl's father, 41-year-old Mark Lunsford, and grandfather, 72-year-old Archie Lunsford, Dawsy said.

Jessica hasn't been seen since Feb. 23, after her grandmother she says she tucked her into bed at the family's home, about 60 miles north of Tampa. Her father had slept at his girlfriend's house that night and discovered the girl missing when he returned home about 6 a.m. Dawsy has said that his story checked out.

An intense sweep using search dogs and hundreds of volunteers ended after five days with no important evidence found.

A 14-member task force is investigating the case, which includes the FBI (search), Florida Department of Law Enforcement, Hernando County and Citrus County sheriff's office. The National Center on Missing and Exploited Children has also provided expertise in helping crack the case.

The reward for Jessie's safe return and information of her whereabouts had grown to $115,000. Atlanta Braves pitcher Mike Hampton, who grew up in Homosassa (search), donated $25,000.

FOX News' Orlando Salinas and The Associated Press contributed to this report.