Every day across the United States, investigations slow or stop, causing cases to go unsolved. Many police agencies lack the manpower, equipment, and funding to support units dedicated to investigating and analyzing older, unsolved cases without additional leads, evidence, or witnesses. As police departments’ active cases became backlogged, those cases lacking “solvability factors” do not receive significant follow-up investigation.

However, continuing advances in DNA technology mean that biological evidence from a crime scene that might not have yielded conclusive results a few years—or decades—ago may now be successfully analyzed using newer techniques. Police departments are now using various forensic techniques to take a new look at their older, unsolved cases.