Hard Evidence

In reality, fingerprint matching takes days to weeks using AFIS, or Automated Fingerprint Identification Systems, the computer database that searches for matches against the prints of persons arrested in a given state or region. Even then, the computer database spits out not one but an array of close matches, leaving it to the investigator to make the painstaking side-by-side print comparisons.




As for getting a match for a DNA sample lifted from a crime scene, try months to over a year, depending on the backlog of cases being run through such state and national databases as CODIS, or Combined DNA Index System. "All you can do is submit your evidence and take a number," says Horne. "Our case may be important, but so are those of every other agency in the state."




All agree that the show has wildly distorted crime victims'
expectations as to what investigators can or will do. "One lady demanded to know why I wasn't swabbing her windowsill for DNA," relates Mississippi detective Craig Burdett. "Even if I could get a sample, we're not going to run a $500 DNA test over a $50 stolen TV."




Whether they come from rural sheriffs' offices or big-city police departments, every one of these crime scene investigators knows the frustration of begging for funds to pay for outsourced tests such as DNA fingerprinting, as well as the basic chemicals and equipment needed for evidence processing. "Just because we know how to do it doesn't mean we'll get the materials," explains Horne. "So while we appreciate all the cutting-edge stuff we've been learning, the best is when they give us the Wal-Mart version."




Which explains why the class's hands-down favorite technique is an on-the-scene print-lifting method learned in
Week 3. It employs superglue and cigarette ashes in a jerry-rigged print-fuming chamber made from a Styrofoam cup. They also enthuse over recipes for fingerprint-lifting gels and strips cooked up using dollar-store items like glue sticks, glass cleaner and a dozen-odd types of duct, masking and adhesive tapes. "Our department's a lot more likely to let us buy a $3 stick of Elmer's blue glue than a $25 bag of chemicals," Horne says.




Eager to apply their new tricks, the students mull the convictions that might have been: "For years, I've been trying to get prints off the cheap sandwich bags our druggies stuff with marijuana and crack," says crime technician Steve Smith of Montgomery, Alabama. (Apparently, higher-grade Ziploc bags give up their secrets more easily.) But now Smith knows a correspondingly cheap trick that will bring out prints on the flimsiest of plastic. Using an ordinary aquarium as a fuming chamber, he will heat a few drops of superglue to create a cloud of whitish fumes that adhere to the print's amino acids. He'll then gently stretch his evidence across an embroidery hoop and spray the print (faint white from the superglue) with a fluorescing dye so that it pops up bright orange for a photograph clear enough to run through the AFIS database.