The faces seem to float from his computer - morgue photographs, artist sketches, forensic reconstructions - thousands of dead eyes staring from Web sites as though crying out for recognition. John and Jane and Baby "Does" whose bodies have never been identified.
His wife, Lori, complains that Matthews, 37, spends more time with the dead than he does with the living. You need a hobby, she says, or a goal.
I have a goal, he replies, though he describes it as a "calling".
He wants to give "Does" back their names.
His obsession began two decades ago, when Lori told him about the unidentified young woman wrapped in canvas whose body Lori's father had stumbled on in Georgetown, Ky., in 1968. She had reddish brown hair and a gap-toothed smile. Locals named her "Tent Girl."
Tent Girl haunted Matthews. Who were her siblings? What was her name?
Matthews began searching library records and police reports, not even sure what he was seeking. He scraped together the money to buy a computer. He started scouring message boards on the nascent Internet.
In the process, Matthews discovered something extraordinary. All over the country, people just like him were gingerly tapping into the new technology, creating a movement - a network of amateur sleuths as curious and impassioned as Matthews.
Today the Doe Network has volunteers and chapters in every state. Bank managers and waitresses, factory workers and farmers, computer technicians and grandmothers, all believing that with enough time and effort, modern technology can solve the mysteries of the missing dead.
Increasingly, they are succeeding.
The unnamed dead are everywhere - buried in unmarked graves, tagged in county morgues, dumped in rivers and under bridges. There are more than 40,000 unnamed bodies in the U.S., according to national law enforcement reports, and about 100,000 people formally listed as missing.
The premise of the Doe Network is simple. If the correct information - dental records, DNA, police reports, photographs - is properly entered into the right databases, many of the unidentified can be matched with the missing. Law enforcement agencies and medical examiners' offices simply don't have the time or manpower. Using the Internet and other tools, volunteers can do the job.
And so, in the suburbs of Chicago, bank executive Barbara Lamacki spends her nights searching for clues that might identify toddler Johnny "Dupage" Doe, whose body was wrapped in a blue laundry bag and dumped in the woods of rural Dupage County, Ill., in 2005.
In Kettering, Ohio, Rocky Wells, a 47-year-old manager of a package delivery company, scoots his teenage daughters from the living room computer and scours the Internet for anything that might crack the case of the red-haired Jane Doe found strangled near Route 55 in 1981.
And in Penn Hills, Pa., Nancy Monahan, 54, who creates floor displays for a discount chain, says her "real job" begins in the evening when she returns to her house, turns on her computer and starts sleuthing.
Monahan's cases include that of "Beth Doe," a young pregnant woman strangled, shot and dismembered, her remains stuffed into three suitcases and flung off a bridge along Interstate 80 near White Haven in December 1976. And "Homestead Doe," whose mummified body was found in an abandoned railroad tunnel in Pittsburgh in 2000. Her toenails were painted silver.
"It's like they become family," Monahan says. "You feel a responsibility to bring them home."
And Laura Allen Hood of Fort Smith, Ark., was searching for her brother.
For years, Hood refused to speak about Tony, who vanished without a trace in 1978 while visiting friends in Oklahoma. He was 16, two years older than his sister.
Hood describes years of false sightings and false hope - stalking someone in a car because he looked like Tony, picking up hitchhikers who bore a resemblance, her mother wrapping a Christmas present year after year for the son who never came home.
It wasn't until 2004, when Hood's own son became a teenager that she decided to find her brother once and for all. Trolling the Internet she discovered the Doe Network. Sifting through its vast indexes, she found new reason to hope.
Hood e-mailed Matthews in Tennessee: "Can you help me find my brother?"
Matthews responded with a series of questions. Was the case filed as missing with the National Crime Information Center, an FBI clearinghouse? Did she have dental records or relevant medical information? Had the family submitted DNA to law enforcement?
Finally, Matthews asked for a photograph of Hood's brother, which he forwarded to one of the professional forensic artists who donate time to the network.
Nothing prepared Hood for the black-and-white image that filled her computer screen a few weeks later - the artist's depiction of a middle-aged Tony. Was he alive? Dead? Did she really want to know?
Four years later, Tony Allen has still not been found. But Hood says she feels a new sense of certainty that someday, someone will click on a mouse and find a connection.
Matches can be triggered by a single detail - a tattoo, a piece of clothing, a broken bone. It's just a question of the right person spotting the right piece of information and piecing together the puzzle. The process can be tedious and frustrating; months or even years of late-night clicking on a dizzying array of sites can often lead nowhere.
Still, Matthews and others say the rewards of cracking a case make the time worthwhile. The Doe Network claims to have assisted in solving more than 40 cases and ruling out hundreds more.
Successes are not entirely joyous, says Doe volunteer Kylen Johnson, a 38-year-old computer technician from Clarksburg, Md. "On the one hand, you are giving families the information they have been searching for. On the other, you are extinguishing all hope that their missing loved one will be found alive."
"Nothing you find can be any worse than something that has already gone through your mind," says Mary Weir of Palmer, Alaska, describing the sickening moment when she spotted an artist's rendition of her 18-year-old daughter's face on the Network.
Samantha Bonnell had been missing for 19 months. She was killed while running across a California highway in 2005, and buried in an unmarked grave - Jane Doe #17-05.
"Her name wasn't Jane Doe," Weir said, her words punctuated by sobs.
"She was Samantha, my Samantha and she had curly red hair and green eyes and freckles on her face. And she was a real person and she was loved. She wasn't just a number."
Today Weir lobbies for state legislation making it easier to file missing-persons reports for people 18 and over - some local authorities are slow to pursue missing adults, saying they have every right to go missing - and mandating DNA samples be taken from family members within 30 days of a report being filed. Several states already have such laws and many others are considering them.
"They do God's work," says Mark Czworniak, a homicide detective in Chicago who has no hesitation about working with civilian volunteers, especially those willing to devote endless hours to cold cases that he cannot get to.
Such praise was rare in the early days of the network, when overeager members were more likely to be derided as "Doe nuts" by police. That changed partly as the organization imposed stricter rules on who could join and developed a system of area directors, researchers and media representatives.
In another sign of the network's influence, Matthews was asked to serve on a government task force involved in creating the first national online data bank for missing and unidentified.
The National Missing and Unidentified Persons System, NamUS, launched last year, is made up of two databases, one for the missing and one for the unidentified. The goal is to have medical examiners and law enforcement agencies around the country constantly update information on both sites. Next year the sites will be linked and made available for public searching.
No one believes NamUS will put the Doe Network out of business - there will always be a need for people with their expertise to make the necessary connections.
And so, families of the missing continue to turn to people like Todd Matthews.
At his house in Livingston, Matthews has built a little nook next to the living room - his "Doe office," he calls it. His desk is laden with pictures of dead bodies. He says he gets hundreds of e-mails about cases every week. Every night he scrolls down the lists, searching for new information.
And every few months he drives to Kentucky, to a lonely plot in Georgetown to visit the "Doe" that changed his life.
Standing by her grave, he tells of the night in 1998 when, scouring chat rooms for the missing, he stumbled upon a message from Rosemary Westbrook of Benton, Ark.
Westbrook sought information about her sister, Bobbie, who was 24 when she went missing 30 years earlier. Bobbie had married a man who worked in a carnival, and she was last seen in Lexington. She had reddish brown hair and a gap-toothed smile.
In his heart, Matthews knew.
Lori, he cried, racing into the bedroom and shaking awake his wife
"I've found her. I found Tent Girl."
E-mails were exchanged. Phone calls were made. When Matthews received a photograph of Westbrook's sister, he had no doubt. She looked just like the forensic artist's portrait sketched years earlier - the one engraved on Tent Girl's headstone, the one that had obsessed him for years.
Weeks later the remains were exhumed. The match was confirmed by DNA.
"It was the best peace of mind in the world," Westbrook says. "What Todd did for our family ... I can't describe it ... I don't have the words. Just to have a grave to visit means everything when you have been wondering for so long."
The family decided to re-inter Taylor in the place that had been her resting spot for so many years. Beneath the stone etched "Tent Girl" they placed a small gray one engraved with her real name, the name that Matthews had restored.
She was Barbara Ann Hackmann, now and for eternity.