DNA database: It ain’t no thang

Elton Wong

A 21-year-old murder case has recently been solved in New York, and new techniques in DNA “fingerprinting” made it possible. This case highlights the potential and the dangers of genetic technology.

On August 29, 1979, Diane Gregory was stabbed to death in her Mount Vernon, New York apartment. Police initially suspected Walter Gill, an acquaintance of Diane who had been convicted seven times in the past. Gill had an alibi, however, and was released.

On the 20th anniversary of the killing, Diane’s sister Carole spoke with a Mount Vernon City Councilman about contacting police to re-examine the case. Capt. Robert Kelly went through the old evidence and discovered that a trail of blood was found at the crime scene, leading from Diane’s apartment to the sidewalk below. At the time, police analyzed the blood. However, in 1979 the technology to analyze DNA was available, so investigators could only blood- type the sample. Blood-typing, unlike DNA analysis, cannot pinpoint specific individuals, because there are only eight possible blood types.

When studying the evidence, Capt. Kelly found old blood samples from the killing. Although the samples had not been properly stored, investigators were able to extrapolate DNA from them.

Once the DNA evidence was collected, police began searching for Walter Gill, the original suspect. When they typed Gill’s name into the police information database, they found that he was already in a state jail serving a 10-to-20 year sentence for armed robbery.

In addition, they also found that Gill’s DNA was already on file. New York, like every other state, requires all violent felons to submit a blood sample to the state, which is then entered into a DNA database. Gill was not considered a violent felon, but New York law also requires that blood samples be taken from non-violent felons as well.

Thus, police were able to compare Gill’s DNA profile to the DNA they recovered from the scene of Diane’s murder. The two profiles matched, and Gill confessed. The murder was solved.

DNA evidence can be extremely helpful to law-enforcement agencies, as this case illustrates. However, civil activists have argued that taking DNA samples violates constitutional guarantees of privacy (such as “unreasonable search and seizure”) even though the courts have held that this is not so.

Civil libertarians have also pointed out that a person’s DNA can reveal what genetic diseases the person is prone to and (possibly) what kind of crimes they are likely to commit. In addition, because each person’s DNA is unique (except in the case of identical twins) DNA evidence can identify individual people, not just groups of people, as was the case with blood-typing.

The advances in genetic technology certainly have potential to be misused. For instance, New York Gov. George Pataki wishes to expand the practice of DNA sampling to include those that commit serious misdemeanors in addition to just felonies. This may be going too far, as making a fake ID is considered a serious misdemeanor.

However, before we all start making knee-jerk references to certain books by Aldous Huxley or George Orwell, there are a few things we should keep in mind.

First, when a person’s “DNA” is entered into a database, this doesn’t mean that a person’s entire genetic code is on file.

As any genetics student will tell you, this is an obscenely large amount of information, most of which is not necessary in a criminal investigation.

Instead, a person’s DNA is used to generate a sort of graphic, a “fingerprint.” This graphic is generated by taking a DNA sample and “cutting” it with restriction enzymes. Because these “cutting” enzymes only cut at certain sites, and because each person has a different base pair sequence, each person’s DNA yields fragments of different lengths when cut by these enzymes. These fragments are then run through a gel, so that large pieces of DNA are separated from smaller ones according to a characteristic gradient.

When of these DNA pieces are run through a gel they create the unique genetic “fingerprints” used by law-enforcement agencies.

The blood samples are destroyed after the “fingerprints” are made, and these pictures do not contain any information about a person’s genes or genetic predispositions. Most news sources are not careful about making this distinction, even though it is a vital one.

Used in this way, genetic fingerprinting is not really much different from regular fingerprinting, it just sounds a little spookier because the word “genetic” is involved.

State DNA databases have become invaluable law enforcement tools. What is needed now is a national DNA database. Even critics of DNA-based technology agree that this system is the best. Right now, each state has its own database.

This is not optimal as it hinders criminal investigations between states as well as FBI investigations.

In addition, a national database with accompanying laws would help prevent “genetic discrimination” and promote uniformity in operating procedures while minimizing abuses.

Great Britain adopted a national DNA law in 1999 and over 70,000 crimes have been solved since by matching crime-scene DNA to profiles in databases.

While we must watch for abuses and misapplications of genetic technology, we should not fear a national DNA database for violent criminals.

Such a database would help law enforcement apprehend rapists and murderers, and would not invade privacy any more than regular fingerprinting does.

In general, it is not a good idea to deny society immediate, tangible benefits on the basis of ill-defined fears.