DECATUR, Ga. -- The search for a missing Gwinnett County hiker continues Saturday.

Meredith Emerson, 24, was last seen Tuesday hiking on Blood Mountain in Union County.

Friday night, police loated a person of interest in the case.

Gary Michael Hilton, 60, was found at a Chevron gas station on Ashford-Dunwoody Road in DeKalb County. He was questioned by police, but the Atlanta Journal-Constitution reported Saturday that Hilton has not been cooperative with police.

No charges have been filed against Hilton. Witnesses have told authorities they saw Hilton talking to Emerson the day she disappeared.

Police located Emerson's dog, "Emma", a 1-year-old black Labrador retriever, at a Kroger parking lot at the intersection of Georgia highways 306 and 400 in Forsyth County, roughly 60 miles from the search site.

"The dog was positively identified because she had an implanted microchip," said Union County investigator Kimberley Verdone.

Friends said Emerson went hiking with "Emma" on Tuesday. Her 1995 Chevrolet Cavalier was found abandoned Wednesday at the base of Blood Mountain.

Emerson, 24, is formerly of Longmont, Colo., and recently became a resident of Buford, Ga., in suburban Atlanta.

Her roommate, Julia Karrenbauer of Buford, said as many as 100 friends and family members have come to the park to aid in the search. Emerson's father, Dave Emerson of Longmont, Colo., headed to the mountain trails Friday with investigators and rescue workers to help look for his daughter.

"They're frightened, scared and we're all very hopeful," Karrenbauer said of Emerson's parents. "We're all trying to stay really positive here. It's been a really long three days."

Karrenbauer said Emerson is an experienced hiker with a blue belt in martial arts.