After thousands of tips and just as many dashed hopes, police in Washington state are using a year-old surveillance video to try to track down anyone who may have information about the disappearance of 10-year-old Lindsey Baum.
The frustrating case has hit one dead-end after another, but authorities say they're waiting for that one piece of information that will lead to an answer.
"That piece of information that someone may have that to them is completely meaningless, that's going to be the one little nugget that will unravel this mystery," said Grays Harbor County Undersheriff Rick Scott.
The surveillance video, recently released to the public, shows two men -- one in a plaid shirt, another with a young boy -- that the police are hoping to talk to. They were at the Shell gas station around the time that Lindsey vanished on her way home from a friend's house in June 2009.
It was a mile-and-a-half-long route she'd taken nearly every day. A woman who drove her car down the street made eye contact with Lindsey just a few blocks from the little girl's McCleary home. But she never made it.
"I know somebody took her," Lindsey's mother, Melissa Baum, said. "I believe it was somebody she knew or thought she could trust. Meaning somebody she would see as safe."
Baum said she has walked the route her daughter took that night hundreds of times.
"I want to feel her," she said.
"To the person who took my daughter -- if they're a parent and they have any idea what a parents love feels like," Baum said, crying, "I just have to appeal to their heart and to their morals and stop this."
Lindsey's disappearance has hit many hard in this tiny town. Her best friend Michaela Kampen, whose house Lindsey had visited the night she vanished, said she watched her friend leave that night, just like she had dozens of times before.
"She said she has to go and I got up and opened the door for her and I watched her walk past that pole," she said, indicated a spot near her house. "That was the last time I saw her."
No Arrests or Sign of Lindsey Baum After More Than 4,000 Tips, 30 Persons of Interest
Michaela, who described her best friend as "very sweet" with a "loud voice," said she sometimes thinks she sees Lindsey in the street, but it's never her.
"I see someone and they look like a completely different person. They don't look the same," she said, blinking back tears. "They look exactly like Lindsey and then I blink and she's not there anymore."
More than 100 law enforcement agents have hunted for Lindsey with dogs, horses and helicopters. Specialized search teams have been called in and neighbors have been questioned, some of them multiple times.
Over the summer, police and the FBI took a closer look at a 47-year-old man they said had numerous inconsistencies in his story. In July, they searched his car, his home and a storage unit, taking with them several items. Though the man, whose name police declined to release, was added to the list of 30 persons of interest, there still has been no arrest.
"I am never going to stop and I'm not going to let this drop. Ever," Baum said. "And when my time's over, I'll haunt them from my grave."
Click here for more information on the National Center for Missing & Exploited Children. And contact the Grays Harbor County Sheriff's Department for more information or to share tips on the disappearance of Lindsey Baum.