The question of what happened to missing Indiana University student Lauren Spierer has baffled investigators – and drawn the attention of ABC News' Brian Ross and former FBI agent Brad Garrett.
Garrett and Ross have spent the past year reworking the case, talking to those involved in it and discovering new leads.
"I was looking for a case that I thought we could maximize the use of social media to potentially solve it," Garrett said. "If you look at the age of Lauren Spierer and her friends, they use social media day in and day out to connect."
On Friday, their work will be unveiled in an hour-long 20/20 special on RTV6.
"This case has taken us to a number of trails," Garrett said. "In any case where someone is missing, first of all, look in their immediate circle. Because many times when people disappear, if it's not voluntarily, it's because someone in their immediate circle harmed them, or perhaps they died around them and they did something with this person."
Asked whether he thinks in a year's time there will finally be an answer to Spierer's disappearance, Garrett said he believes so -- and he thinks the TV special will help bring that answer to light.
Garrett sat down for a satellite interview with RTV6's Jason Fechner about the special. See what he had to say about his investigation in the video player above.