UNION COUNTY, Ga. -- Both the man police have been calling a "person of interest" in connection with a missing hiker and the missing woman's dog have turned up.

Officers spotted Gary Michael Hilton at a convenience store off Ashford-Dunwoody Road Friday night and are questioning him about the disappearance of Meredith Emerson, 24.

"Meredith was not with him," Union County investigator Kimberly Verdone said. "Six four-man search and rescue teams are in the woods right now searching for her."

Emerson has been missing since Tuesday when she went for a hike with her dog on Blood Mountain in Union County.

The dog, Ella, wandered into a grocery store in Cumming, about 60 miles from where Emerson was last seen and was identified by an implanted microchip, Verdone said.

Hilton, believed to be the last person to see Emerson, was taken to GBI Headquarters in Atlanta for questioning.

An acquaintance of Hilton told Channel 2 that she helped Hilton order an expandable baton like the one found near the missing hiker's car. She said he always had the baton with him.

Union County investigator Kimberly Verdone said 15 professional search and rescue teams searched for Meredith Emerson throughout the day as volunteers traveled across north Georgia and parts of North Carolina to post fliers with pictures of her and "Ella," her 1-year-old Labrador retriever that friends say was with her when she disappeared.

Emerson's roommate, Julia Karrenbauer, said as many as 100 friends and family members have come to Vogel State Park to aid in the search. Emerson's father, Dave Emerson of Longmont, Colo., headed to the mountain trails Friday with rescue workers.

"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."

The Georgia Bureau of Investigation has entered the search and is exploring a possible link to the disappearance of two hikers in North Carolina.

"The last team came at 6 o'clock this morning," Verdone said Friday, as the overnight search for Meredith Emerson continued in daylight hours.

Verdone said multiple teams of search and rescue dogs, along with law enforcement officers and firefighters, were combing a 401 square mile area of rugged terrain.

Fifteen teams of searchers made up of law enforcement, fire and emergency medical services personnel were searching on and near the trail where Emerson was hiking.

Officials said they are only using professional search teams to look for Emerson Friday. Volunteers were still showing up to help and they were being used to pass out fliers.

"Person Of Interest" Sought

Police say they want to talk to Gary Michael Hilton of DeKalb County about the case. They said Hilton, who is in his 60s, drives a 2000-2001 white Chevy Astro van. He was reportedly seen several times on New Year's Day with Emerson.

"We have talked to a lot of people who saw them together," said John Cagle of the GBI. "We know he was there."

Cagle also confirmed GBI agents are talking to investigators handling the presumed murder of two hikers in North Carolina.

John and Irene Bryant disappeared Oct. 20 while hiking in North Carolina's Pisgah National Forest. Her body was found three weeks later; she had been beaten to death. Her husband is still missing.

Someone wearing a yellow jacket used the couple's ATM card at a bank about an hour north of where Emerson was hiking.

Police say Hilton was wearing a yellow jacket when he was seen talking to Emerson.

Emerson, 24, originally from Colorado, but living in Gwinnett County, has been missing since she went hiking on Blood Mountain Trail in Union County on Tuesday.

Friends believe she spent Tuesday, Wednesday and Thursday night outside in the cold north Georgia mountains. Temperatures reached into the teens those nights. Her roommate said Emerson is an experienced hiker familiar with the mountains.

"Let me tell you something, Meredith Emerson can do anything," said family spokesperson Peggy Bailey. "She's a strong person."

Other hikers who were on the trail Tuesday told authorities they saw Emerson talking to a white male, 50-60 years old, described as "weathered looking" with missing teeth. Officials now believe that man was Hilton. The man had a red dog with him he called "Dandy." Officials said they want to talk with Hilton because he was seen with Emerson throughout the day Tuesday.

"It's not that, you know, he's a suspect. He is somebody that was last seen talking to her, last seen with her," Verdone said during a Friday morning news conference.

Union County officials are asking anyone with information on Hilton's whereabouts to give them a call. It's possible Hilton is driving a 2000-2001 white Chevy Astro van with DeKalb County plate AFQ 1310.

Little is known about Hilton. He was convicted of two felonies; one for the possession and distribution of marijuana, another for theft by taking. According to public records, his last known address was on 11th Street in Atlanta in 1999.

The man they believe was Hilton had a sheath of some sort on one of his legs, Verdone said, but police don't know what was in it. He was wearing a yellow jacket and a large backpack -- "something you would use for a couple of days," she said.

Anyone with information about Hilton should call the Union County Sheriff's Office at 706-439-6038.

"We want to find out who he was and kind of talk to him and see what happened and what their conversation was throughout the day," Verdone said.

Emerson's roommate said Emerson left a note saying she went hiking with her dog. Authorities said they have located Emerson's car -- a Chevy Cavalier -- and her dog's leash, but they have found no sign of Emerson or her black Lab, Ella.

Police also found a police baton and a pair of sunglasses near Emerson's car.

Another hiker told officials he saw a man with a similar baton clipped to his belt hiking on the same trail that Emerson took.

Hilton Acquaintance Says He Always Carried Baton

An acquaintance of Hilton’s told Channel 2 he would frequently walk his dog, Dandy, along Clairmont Road in DeKalb County. She said he also loved to hike in wooded areas. She said from what she saw, Hilton was usually friendly.

“He’d talk your ear off. (He was) very, very talkative and friendly to me,” said Barbara – who asked us to only use her first name. Barbara said 61-year-old Gary Hilton lived and worked inside a two-story building near her office for almost 7 years.

"He'd come over and he'd ask me to do computer searches for him and make up flyers for him,” said Barbara.

He distributed promotional flyers to drum up business for a siding company. Its owner, John Tabor, also owns the building and told Channel 2 he has been cooperating with the GBI. Agents said Hilton was the last person seen with missing hiker Meredith Emerson. Her black dog, Ella, is also missing and was playing with Hilton’s Golden Retriever, Dandy, on a trail in Vogel State Park.

“He seemed friendly and I could see if the girl had a dog and he had a dog and the dogs were playing that yeah they'd chat and walk along,” said Barbara.

She said Hilton, who uses the nickname “Mack,” always told stories about people he’d meet on the trails. When he left DeKalb County two or three months ago, Barbara said she was surprised.

"I do know he has Multiple Sclerosis. He's in a lot of pain. He once told me he had about 6 years to live and that was a couple years ago and I was surprised when he told me he was going to go live in the woods cause that's a big step when you're ill,” said Barbara.

She said Hilton always carried an expandable baton with him. Barbara ordered it for him off the Internet. A baton was found along the trail near Emerson’s water bottle and her dog’s leash.

"I'm surprised, I really am. He seemed to treat ladies very nicely, certainly me and the other secretary that worked here before, never had any problems, or got the feeling that you needed to be on guard."

Over the years Hilton has moved around quite a bit and had several run-ins with the law. Channel 2 found at least five arrests in DeKalb and Cobb Counties – both misdemeanors and felonies. Agents have not named his as a suspect in the case, only a person of interest.

GBI Joins Search

At the request of the Union County Sheriff's Department, the Georgia Bureau of Investigation sent four agents to join in the search Thursday morning, GBI spokesman John Bankhead said.

The Georgia State Patrol pitched in with a helicopter using an infrared device. The helicopter had been grounded by high winds on Wednesday.

"She's an experienced hiker and a blue belt in martial arts," said Julia Karrenbauer, Emerson's roommate. "She's athletic and has a good head on her shoulders. So we're just hoping for the best."

Family members were at the search command post on Thursday.

Union County Fire Department spokesman Lt. Jeff Fortenberry said up to 30 emergency personnel and deputies searched a mountainous, six-mile stretch of trails south of Blairsville on Thursday. He said investigators have found no signs of foul play.

Temperatures reached 13 degrees with the wind chill factor in the single digits Wednesday night. Union County received snow Tuesday night -- which canceled classes for that school system Wednesday, Thursday and Friday.

Emerson is 5'4", 120 pounds with blonde hair and blue eyes.

One of Georgia's oldest and most popular state parks, Vogel is located at the base of Blood Mountain in the Chattahoochee National Forest.