The first case involves 31 year-old pacemaker salesman Joel Marino, who is found brutally murdered in an alleyway next to his house in Madison, Wisconsin, one of the safest cities in America with 9 homicides a year. The weapon? A simple paring knife. Witnesses saw a man fleeing the scene wearing a knit cap and a backpack. Both items were discarded and found; DNA on them and the knife led to the killer. In the second segment, a serial killer of four college coeds in southern Illinois is not proved for 32 years. Although convicted twice for violent attempts to subdue coeds and finally for one of the murders, no link is available to the others. Exhuming the suspect's body to get DNA and new developments in analysis were necessary to finally close these cold cases.