[Lady Sidhe]

Reader's Digest, June 2004



There is a new DNA test that can determine a person's ancestry. Standard DNA tests can determine sex, but tell nothing about a person's appearance.

While prosecutors today routinely use DNA taken from a crime scene to convict an offender, the analysis does not tell police much about whom they should be looking for in the first place. Widely used tests today only reveal a person's sex, but that's changing. Using a huge database of of genetic information from people all over the world, scientists at Penn State University devised a test that looks for "markers" on DNA that give strong clues about a person's ancestry.

The test, known as DNA Witness, can determine whether a person is most likely European, African American, Asian or Native American (people of Hispanic heritage tend to have a mix of ethnic groups.) Crime researchers in Britain are currently working on a test that they hope will detect hair color and even facial characteristics.

Scientists at the University of Ottowa Heart Institute have a method for extracting DNA from the microscopic remnants of skin left behind when a person touches an object. The test can be performed in minutes at the crime scene. The process, which is not available yet, also works for blood, hair, saliva, or even a flake of dandruff.

Researchers are also perfecting ways to identify plant DNA, which would have many uses, including the ability to trace seized shipments of illegal drugs to a given distributor.
Forensic scientists are developing methods to identify animal DNA. One in three homes in the US contains a source of criminal evidence: a cat or dog. As pet lovers know, fur clings to clothing. In one celebrated case, police on Prince Edward Island, Canada, linked white hairs on a bloody jacket found near the scene of a murder to their prime suspect--who owned a cat named Snowball.

Police in Kirkland, Washington, were frustrated. They had a suspect in the murder of a 27-year-old Bible-studies student: her neighbor, Eric H. Hayden. They also had a bed sheet with a bloody hand print. But the pattern on the fabric caused the finger- and palm prints to be unclear, making it impossible to match them to Hayden's hand. Enter Eric Berg, a forensic field supervisor with the police department in nearby Tacoma. Berg took digital photos of the prints and, using a computer program, filtered out the background "noise," producing clear prints that helped convict Hayden, who is now serving 26 years in prison.

Looking for fingerprints remains an essential part of any crime-scene investigation. However, criminals rarely leave behind pristine impressions. Berg's innovative technique, which is now available in police departments in the form of software called More Hits, enables police to read smudged or partial prints.

There is also an FBI-run database called CODIS (Combined DNA Index System), which is a network that lets Federal, State, and Local crime labs exchange and compare DNA electronically. The genetic information in question merely has to be plugged into the system. Using this system, Kansas City police were able to trace the murder ofr a 39-year-old woman (in 2000) to a paroled rapist from Arkansas named Wayne Dumond, who is now serving a life sentence for the murder.

Using computers, scientists at the Heinz School at Carnegie Mellon University in Pittsburg tracked minor and major crimes for more than a decade in two cities (Rochester, NY, and Pittsburg, PA). After running extensive statistical analyses, the scientists discovered that an uptick in minor crimes such as vandalism usuallly precedes, by about a month, more serious property crimes, such as burglary and larceny.

When the researchers road-tested their program, they were able to predict crimes with at least 80% accuracy. What's more, they could narrow down where the crime would take place to an area as small as an individual police beat--about one square mile. By the end of this year, the researchers hope to begin distributing the software to precincts across the country.
While criminals often seem to strike in a random fashion, statistical analyses of crime locations can disclose patterns. That's useful when police are hunting for serial criminals, says Texas State University criminologist Kim Rossmo, who created a concept called Geographic Profiling. Rossmo notes that criminals tend to commit crimes close to home--but not too close ("comfort zone", in profiling terminology). He has developed software that analyzes an area where linked crimes have occured, then isolates a tiny section where the crook most likely lives. That allows police to focus on specific suspects. In one case, police in Midland, Ontario, used Geographic Profiling to nab a prolific burglar. The system nearly drew a circle around the suspect's home.

Analytical scientist Peter Nunes, of the Forensic Science Center at Lawrence Livermore National Laboratory, part of the US Dept. of Energy, shrank a standard gas chromatographer-mass spectrometer (a bulky instrument, weighing between 200-250 lbs., used to identify organic compounds by vaporizing them and analyzing the resulting gas molecules.) However, transporting substances such as chemical weapons, explosive residues, fire accelerants, and drugs--to crime labe takes time and can be dangerous; therefore, the new and improved GC-MS has been shrunk to a a portable 75 lbs. It is already on the market and is in limited use by the Los Angeles County Sheriff' Dept.



Now that's interesting.....



Sidhe