Authorities have arrested a man in Missouri who they say is a second suspect in a 20-year-old murder case. The body of Karen Weber was found in April of 1986 near a gravel road northwest of Prairie City, dead from multiple stab wounds.

Prosecutors say DNA tests led them to arrest 48-year-old Martin Duffy of Des Moines this week. Last night Jasper County deputies went to Eldon, Missouri, and arrested 45-year old James Lee Cox. Jasper County Sheriff Mike Balmer says Duffy led them to the second suspect. They’d been working with the Division of Criminal Investigation on Duffy’s background and associates, and Sheriff Balmer says they learned things about Cox that made them think "he might be an unidentified co-conspirator."

They went to Missouri, interviewed the second man, and arrested him. The case was re-opened after law enforcement officials matched a D-N-A sample from Duffy with the evidence in the unsolved 1986 slaying. Balmer says with today’s improved DNA technology, cases can be solved years after they seemed hopeless.

"Sometimes it takes 20 or 30 years, but new technologies allow evidence to be resubmitted and new things can be learned. Balmer says they resubmitted evidence to the state crime lab in 2000, and got a DNA match in 2006. Balmer says, "You try every avenue, and sooner or later, justice is served."

Balmer says the investigation continues. The sheriff says they’re still following other leads and tie up the loose ends but thinks "We’ve got out two main players in this." Duffy and Cox are both charged with first degree murder. The criminal DNA database has 23,000 profiles in it today, and investigators say last year it enabled the crime lab to put a name to 77 previously unidentified DNA samples in the files.