The biggest “enemy” of a cold case is time. It it affects memories, evidence and paper reports. But time also can bring breakthroughs by way of new technology that wasn’t available when someone was killed and murders went unsolved. In a continuing series, The Gazette will revisit some of those unsolved cases in Cedar Rapids and Linn County. Investigators will share their insights and new information gathered over the years, and victims’ families will share memories of their loved ones.