As searchers narrowed their hunt for a missing Buford hiker to a 5-mile area in the Chattahoochee National Forest, the "person of interest" connected to Meredith Emerson's disappearance was in the custody of the U.S. Marshals Service.

U.S. Marshals spokesman James Ergas told The Atlanta Journal-Constitution at 1:10 p.m. Saturday that Gary Michael Hilton, 61, was in custody on an outstanding bench warrant. The warrant was issued several months ago when Hilton did not appear in federal court on a charge of abandoning property in a national park.

Brant Sanderlin/AJC

GBI officials wouldn't confirm media reports that some of Meredith Emerson's belongings were found in a dumpster outside this Quik Trip on Keith Bridge Road in Cumming, not far from the Kroger where Emerson's dog was found. WSB reported that officials searched the dumpster, dusted a pay phone at the Quik Trip for fingerprints and had removed the receiver from the phone.

Kimberly Smith/AJC

A white van sits near an outdoor vacuum cleaner unit at a Chevron station at the corner of Johnson Ferry Road and Peachtree Dunwoody Road in DeKalb County Friday night at about 11 p.m., shortly after a GBI Crime Scene Unit arrived to go over the van. Gary Michael Hilton, who is a 'person of interest' in the disappearance of Meredith Emerson, was discovered at this station with the van Friday night.

Family photo

Meredith Emerson with her dog Ella.

RELATED LINKS: • Search for Meredith Emerson intensifies • Photos: The search • Photos: 'Person of interest' found • Video • Does yellow jacket link two cases? •More Gwinnett news

Hilton is expected to appear before a federal judge on that charge Monday.

Earlier Saturday, Forsyth County Sheriff Ted Paxton told the AJC Hilton was not cooperating with authorities investigating the disappearance of Emerson, who was last seen on New Year's Day in the North Georgia mountains.

Hilton, 61, was found Friday evening by DeKalb County police at a convenience store along Ashford-Dunwoody Road, authorities said. Believed to have been the last person to see the 24-year-old Buford woman, Hilton was spotted by other hikers at Vogel State Park as he and Emerson walked up Freeman Trail on Blood Mountain.

Hilton, 61, remained at an undisclosed location and is being questioned in the disappearance of Emerson, whose dog, Ella, turned up Friday at a Cumming-area grocery store.

Paxton said Saturday that investigators have surveillance tape showing that Hilton had been in the area where the dog was found, but added, "We don't have the luxury of him cooperating in the search for the woman."

Search continues

Meanwhile, the search continues. Shortly before noon Saturday, authorities said they were focusing their hunt on a 5-mile area of rugged terrain in the North Georgia mountains about 90 miles north of Atlanta.

GBI spokesman John Bankhead confirmed shortly before 2 p.m. Saturday that federal agencies, including the FBI, have joined the investigation because the incident happened on national park land.

The area searchers are now focusing on is near where Emerson's 1995 Chevrolet Cavalier was found after her New Year's Day appearance, said Kimberly Verdone, a spokeswoman for the Union County Sheriff's Office. Verdone wouldn't disclose what led officials back to that area, which searchers have already scoured while covering 401 miles the past three days.

A team of about 100 volunteers planned to join professional searchers early Saturday afternoon. The volunteers had been anxiously awaiting marching orders since arriving at 8 a.m.

One of the volunteers, Angie Bogen, said at 11 a.m. that authorities told them there was a "new development" that had held up the search. Bogen, 30, of Lawrenceville, said she was a friend of Emerson's.

Searchers have had to work in rugged, hilly terrain that rises from 3,000 to 4,500 feet above sea level and still has remnants of snow that fell Tuesday evening. Temperatures have ranged from the mid-20s to the mid-40s.

Personal effects found

Investigators found "personal effects" of Emerson's in the area where Hilton was found, Paxton said Saturday.

The Union County Sheriff's Office and the GBI had been searching for Hilton since late Thursday to talk to him about Emerson.

DeKalb County police spokeswoman Mekka Parish said officers detained Hilton after receiving two calls about 7:40 p.m. Friday — both calls reported possible sightings of Hilton at the Chevron gas station in the 3500 block of Ashford-Dunwoody.

When officers arrived, they found Hilton and confirmed his identity, Parish said. They also found a dog in Hilton's white van, and it was taken to an animal shelter in DeKalb County.

Parish said DeKalb police had been helping in the efforts to find Hilton, whose last known address was in the Atlanta area.

A spokeswoman for the Emerson family, Peggy Bailey, said lthe family is optimistic that Hilton will have information that will help the investigation, calling him the "missing link."

"We just feel certain that this is going to lead us to Meredith's whereabouts," she said. "If he doesn't know, he'll know someone who does."

'Dog means everything to Meredith'

The family was buoyed by news that Emerson's beloved Labrador mix, Ella, was found unharmed.

GBI spokesman John Bankhead said Emerson's dog was found about 3 p.m. Friday at a Kroger store in the Cumming area. Officials said a chip in the dog was used to confirm its identity.

"That's wonderful," Bailey said of Ella's discovery. "The dog means everything to Meredith. When we find Meredith, that's the first thing she's going to ask: 'Where's Ella?' "

Meanwhile, the family will continue the search for Emerson.

"I can't be happy until we know Meredith's OK," Bailey said.

Emerson's friends produced fliers and a Web site — helpfindmeredith.com.

— Staff writer Rhonda Cook contributed to this article.