Killer Unknown

America's finest detectives come out of retirement to crack open 31 cold cases in Tulsa County, Oklahoma, starting with the 1998 murder of Dena Dean and the 1973 murder of Veda Woodson.

A massive effort to contact Dena Dean's best friend culminates in a hopeful first contact. Conversations reveal a tense relationship Dena had before her murder, prompting the task force to take a fresh look at alibis.

A devastated family recounts the horrifying moments leading up to the murder Veda Woodson on a deserted road. On the Dean case,investigators arrive at a shocking conclusion after looking into Dena's family.

Pressure builds as Mike Huff narrows is focus to a man who was Dena Dean's boyfriend in 1998 and one of the last people she had contact with on the day of her disappearance.

Phones are confiscated with a new plan to comb through communications between persons of interest in the Dena Dean case, while Mike Huff thinks a suspect's family may be hiding something in the Veda Woodson case.

The task force races to put the evidence they've collected in the Dena Dean case towards prosecution. A shocking new DNA breakthrough keeps the Veda Woodson murder case from going cold for good.