Where is Dail Dinwiddie?

You would find it tucked away in the corner of Columbia Police Investigator Mark Vinson's office: The battered black filing cabinet packed with almost 20+ years of documents, clippings and reports.

All generated by the massive, and to this day, unproductive probe into the disappearance of Dail Dinwiddie.

"We're still working on it," said Vinson. "If leads come in, we're still willing to look into them. If someone, if we have people that come forward to say they saw something that night and they just decided to come forward 15 years later, we're still willing to listen to what they have to say."

In September of 1992, the Irish rock band U2 brought its "Zoo TV" tour to Williams-Brice Stadium.

Among tens of thousands there was the petite 23-year-old art history graduate who'd recently moved back to Columbia to live at home and continue her schoolwork at USC. After the concert, Dail and her friends went to a Five Points bar called Jungle Jim's.

A couple of hours later, she separated from the group and was gone.  She is still gone.

And yet, after nearly two decades of anguish, uncertainty and disappointment, Dan and Jean Dinwiddie have not given up.

"Just hoping that this will be the time when someone will hear this and remember something and maybe can give us some information," said Jean. "And we have to find Dail.  I still have hope."

"We love her very much," sad Dan. "We prayed to have her. We reared her. Nurtured her. And to give up now is just not--that's not fair. That's not right.

The search for Dail generated intense publicity, some of it national and even international. There were rallies and ribbons.

The Dinwiddies had to get used to being interviewed on TV and taking their pain to the public.

Psychics stepped forward with so many visions, Jean had to put them in chart form.

Police maintained a sort of war room to collect and track hundreds of leads.  Believe it or not, tips are still trickling in.

"They're all different things," said Vinson. "I mean we still have some psychic leads and then there are also leads, people will tell us that somebody admitted to them that they were involved or suspect that someone was involved."

While Dail's status and the basic facts of the case have not changed, her parents are always willing to explore any option that might lead to a scrap of new and potentially valuable information.

Dail's picture, for instance, is now included on playing cards distributed to prison inmates in hopes that maybe one of them might know or hear something.  Something, anything, that could close the case that was, 15 years ago, the city's oldest unsolved missing persons investigation.

It still is.

"They say that losing a child or not being able to find a child is probably one of the most difficult things in life," said Jean. "And I'm sure that's true. But think how sad it is for the child not to be able to find her parents."

Shortly before we spoke with the Dinwiddies, they marked what would have been, or might have been, Dail's 43rd birthday.  It's always a difficult time of year for the Dinwiddies.

But they both wanted to make it clear that while many people might wonder how they've managed to make it through the many disappointments of the past twenty years, this story should not be about them.

They still wanted the focus to be on Dail. Finding Dail, or finding out what happened to her.

Copyright 2012 WIS.  All rights reserved.