DNA dilemma

Crime | New federal guidelines to expand genetic sampling create more questions over whether more information is too much | Daniel James Devine

LOWELL, Ind.— When a fleck of blood, a hair root, or a body fluid sample arrives at the State Police DNA lab in Lowell, Ind., it may be the only piece of evidence collected from a crime scene. Its value, however, will be high for both victim and criminal: If its DNA matches up in the system, the crime may be solved.

Inside the lab's "layout room," analysts in latex gloves identify DNA-containing material at a large lamp-lit counter. Working with a single sample as small as three millimeters, the DNA analysts use an array of chemicals, filters, and centrifuges to isolate and extract genetic molecules.

In the "amplification room" the molecules are coaxed into replicating themselves. A computerized machine that might have been inspired by Star Trek plunges 16 needles into gene-filled vials, creating EKG-like graphs of about 13 locations on the human genome, which together constitute a standard genetic profile that is unique to nearly every person (identical twins excepted).