corrections center in bonn bonne terre, missouri. why did it take so long? >> reporter: lawyers in this case will tell you they've been trying to get this dna evidence entered into the rofecord and io this case for years and years and they've been stopped by the state at every single turn. this case is nearly two decades old. felicia gayle was murdered in 1998 inside her own home. she had more than 40 stab wounds and that knife was actually left inside her body. you mentioned dna testing was allowed on that knife. it's actually a relatively new dna testing technique they were able to use, and the results, according to the governor, were relatively inconclusive, meaning it was possible, according to some of these analysts, to rule that marcellus williams was not the suspect in this case, or at least his hand was never on the knife, but it wasn't possible to prove whose hand was actually on