updated 01/29/2014 AT 10:00 AM ET
•originally published 01/30/2014 AT 2:30 PM ET
Kristin Spires was just 20 years old in May 2010 when she vanished while driving to a party in Big Rapids, Mich.
Her stepmother, Carolyn, alerted police in her rural Michigan town, and a TV crew met her to report on the family s frantic search.
That evening, even before the broadcast report was finished, Spires phone rang. Heather Holland was on the line.
“She had seen my story on TV,” says Spires, “and wanted to help any way she could.”
Holland sensed the need – just as she has for many other families she’s helped since 2010 – as director of the nonprofit TrackMissing.
By scouring police and court reports as well as the Internet, collecting family medical records and sometimes even hitting the ground herself, the full-time social worker and part-time sleuth has helped families learn the fates of nine missing people.
“The reason I do this is because I could not stand not knowing,” says Holland, 31, of Big Rapids, a married mother of a 5-year-old son.
“I try to work on cases where’s there s not already 100 people looking,” she says. “You can’t find them all. But I hope the families feel better knowing there’s somebody else out there trying to help.”
Holland works hand in hand with law enforcement, who welcomes her assistance.
“We have over 4,400 missing persons cases in Michigan,” says Detective Sarah Krebs of the Michigan State Police.
“I don’t have time to do a web search on every single case,” she says.
“To have somebody like Heather who will do that for us and give us the tips that make a match,” she says, “it’s like they hand us the case on a silver platter.
Krebs recalls a man who disappeared in 1992, and whose then-unidentified remains turned up in another county much later. As a liaison aiding the man’s family, Holland gave police the medical records that led to a positive ID.
“Heather’s a great asset to law enforcement,” says Krebs. “It’s another weapon we can give the families of missing people in their search.”
Holland got started in 2009 when a friend remarked about an aunt who’d vanished as a child decades earlier.
Eager to help, Holland logged in to online forums maintained by families of other missing persons – and learned that adults rarely get the urgent response of Amber Alerts for children.
She didn’t solve her friend’s case, but her search led her to TrackMissing, which had been founded in 2004.
Holland e-mailed the one-man operation with an offer to volunteer.
She taught herself to follow paper trails and master the online National Missing and Unidentified Persons System, maintained by the National Institute of Justice.
When TrackMissing s director took ill in 2010, Holland took over.
She devotes about 20 hours each week in late nights and weekends to her amateur sleuthing.
Once, a record search and a quick call brought a dying woman together with a long-lost brother. But Holland is realistic about the long odds that accompany unanswered disappearances.
“I’m not one to provide a false hope,” she says. “I can’t promise we’ll find them. I just like to give people some closure.”
In Spires’ case, Holland spotted a Facebook tip and followed the lead to a site in the woods. There, 11 months after Kristin vanished, Holland and Kristin’s stepmother located a bone that police eventually ID’d as belonging to the young woman.
Although the case is unsolved, “If not for Heather, we’d still be looking,” says Carolyn Spires, 38, of Moreley, Mich.
“There’s no way to thank somebody for something like that,” says Spires.
“If Heather gets something in her mindset, she’s going to go after it until she gets it,” she says.
“She definitely kept me going,” she says. “She s an awesome, awesome person.”
[RELATED_TEXT “More Heroes Among Us:
Know a hero? Send suggestions to email@example.com. For more inspiring stories, read the latest issue of PEOPLE magazine