An all-new series on Investigation Discovery "Killer Unknown" follows the Tulsa County cold case task force.
One of the cases they're working is the unsolved murder of Dena Dean in 1998. The 16-year-old was taken from the Town West Shopping Center and not seen again until her body was found six days later in a field.
Dena Dean's parents, Diana and Larry, know keeping their daughter's name in the public is the best chance of finding her killer.
"People have to realize that if you don't get involved, there is not going to be somebody to help," Diana Dean said.
The series has re-enactments of Dena Dean's final moments. Her mother said one of the hardest parts for her to watch was the actor's portrayal of her daughter's body being found.
"There is a lot that brought back painful memories, but I know this has to be done," Diana Dean said.
The Tulsa County Cold Case Task Force is led by Mike Huff, a retired Tulsa Homicide Detective. His team was followed around by cameras for more than a year as they sifted through old evidence.
He said at first, it was weird having cameras following the team around. Huff said they gained his trust and have not betrayed it.
Huff said since the first two episodes aired, posts have been made online that have caught their eye. His team is looking into those to see if they could provide new leads in the case.
He believes key players in the case are on the edge of their seat because of Killer Unknown.
"I'm 100 percent certain that the suspects are probably watching to see where we're going, but a lot of this won't be a surprise to them," Huff said.
Huff said he has also had people reaching out to lend their skills to get justice for Dena Dean's family.
Both Diana Dean and Huff said they hope the series encourages retired law enforcement in other states to join together to solve their cold cases.
"We hope to motivate other groups of guys that are sitting at a coffee shop talking about retirement to say, 'Hey, let's do something here,'" Huff said.
The first two episodes are available online and on demand. The next episode will air Dec. 1 at 9 p.m.
Stay in touch with us anytime, anywhere.
Sign up for newsletters emailed to your inbox. Select from these options: Breaking News, Severe Weather, School Closings, Daily Headlines and Daily Forecasts.