The Washington, D.C., medical examiner identified the body of Chandra Levy within hours of its discovery, using Levy's dental records. How do police and forensic scientists identify a dead body?
If police have an idea who the dead person is, common methods include:
1) Visual identification by a friend or relative: "Is this your loved one?"
2) Fingerprints, if enough skin is intact.
3) Dental records, as in Levy's case, where all the police found was a skull and scattered bones. The identification is made by matching any dental work the person had—fillings, caps, etc.—or irregularities like missing or chipped teeth. If the person had perfect teeth, this is more difficult.
4) DNA. To confirm identification with DNA tests, the D.C. medical examiner could either use samples of Levy's parents' DNA or a sample drawn from her toothbrush. DNA samples can be drawn from skin or bone fragments.
If the police are trying to identify a John or Jane Doe, forensic scientists use computer graphics to perform a facial reconstruction to approximate the dead person's appearance. Scientists can determine a person's sex and race from skull features, but they can't discover much about the soft tissue in the ears and nose, or how much fat the person had on his face. They distribute the reconstructed image for possible identification.
Explainer thanks Dr. David Foran of George Washington University and Professor Peter Deforest of John Jay College of Criminal Justice, CUNY.