LONDON -- The police in Britain, famous for their pioneering use of the fingerprint, have taken a leap into the forensic future by embracing the revolutionary identification technique called genetic fingerprinting. But the legal and ethical implications of this virtually foolproof test, which makes use of a person's unique DNA profile, have yet to be rigorously addressed.

While prosecutors puzzle over whether the genetic evidence will be accepted by juries, civil liberties advocates are wondering what will happen to a person's genetic file once he is ruled out as a suspect. Could the "fingerprint" -- which resembles the black-and-white bar code on grocery items -- be used against him at a later date for other crimes?

With but a single drop of blood or semen left by a criminal at the scene of a crime, British police investigators are now able to make powerful links to suspects. If the DNA genetic material from the crime scene matches that of the suspect's blood, the British Home Office -- the government department in charge of domestic affairs -- says there is only a one-in-25-million chance that the wrong person has been identified. British police have already used the technique, developed by a Leicester University scientist, to make arrests in more than 50 criminal cases. Genetic profiling is especially useful in identifying suspects in murder and rape cases, they say.

Concerns in Britain and elsewhere in Europe are paralleling a similar debate going on in the United States, where the first rape conviction based on DNA evidence occurred Nov. 6 in Florida. Scientists at Lifecodes Corp., a New York firm, proved that semen found in the victim's vagina genetically matched the suspect's.

Cellmark Diagnostics, the British company marketing a similar genetic test, opened an office in Germantown, Md., last month. That office has begun testing samples for police investigators from Texas, Florida, Maryland, Virginia and Delaware, according to John Huss, vice president of marketing for Cellmark.

Moreover, the state of California is studying how to add genetic profiling to its computer data base called CAL-ID, which can perform an automated fingerprint search on the state's criminal files. California already requires convicted sex offenders to give blood and saliva samples before their release from prison.

"We believe that DNA, once we put it on line, will have the potential of adding another base to CAL-ID," said Cecil Hider, who is in charge of training and research for the California Department of Justice's forensic services. If a released criminal commits another crime, says Hider, "we'll have their genetic information on file. It's a goal we're working on."

On Nov. 13, a Bristol man became the first Briton convicted directly as a result of the genetic fingerprinting test. Robert Melias was sentenced to eight years in prison for the rape of a 43-year-old physically handicapped woman. He had pleaded guilty after being confronted with the evidence that his DNA pattern matched that of a small semen stain left on the victim.

While all U.S. cases to date have involved tests of specific suspects, Europe has already begun to confront the ethical issues raised when police want to do a "genetic sweep" of an entire town. Civil libertarians in Britain are concerned about what they're seeing. Peter Thornton, a spokesman for the National Council for Civil Liberties in Britain, said, "Basically, we welcome the test. It's excellent, as long as it's properly carried out." But, he said, "there are no statutory guidelines from the Home Office as to how this test should be used. A question of confidentiality arises out of the storing of the information."

"We have no privacy law in this country and no very developed law of confidentiality," he continued. "All the law says at the moment is, when a body sample is given, that sample must be destroyed if the person is acquitted or not charged. It must be destroyed in their presence, but the law says nothing about the information taken from the sample, the data." Thornton sees a big loophole -- the original blood sample could be destroyed, but the genetic information could find its way into a data bank.

There are other complications. The genetic profiling technique requires the cooperation of the suspect. That is, in order to rule himself out as the murderer or rapist, a suspect must provide a blood or saliva sample. British law does not require a suspect to submit to a genetic profiling test -- or even undergo traditional fingerprinting. But the refusal to provide a fingerprint can be used by the prosecution to make a telling point in court, Thornton remarked.

The very fact that a genetic fingerprint test exists might also be a tool in the hands of investigators. In a widely publicized case involving the murder and rape of two schoolgirls, police in Leicester, convinced that the murderer was a local man, asked the entire male population between the ages of 13 and 30 in three neighboring towns to voluntarily submit blood samples -- and the people of Leicestershire County complied. The police set up clinics in the towns and collected about 4,500 samples.

"The public generally was 100 percent behind us around here," said Detective Inspector Alan Ottey. "At the local pub, they wanted him caught and they would do anything to catch him."

A 17-year-old boy originally charged with one of the murders was released because his genetic profile did not match the profile derived from semen left in the victims.

In the end, however, it was the threat of the test, not a DNA matchup, that led to the arrest of a suspect, the local baker. Like everyone in town, he too had submitted to the test. But according to the Home Office, there was "some doubt" about the authenticity of the sample the baker gave, leading investigators to question him.

The case left the police of Leicestershire with a genetic profile on every young man in the county.

"The Leicester volunteers all gave blood samples on the basis of a specific and limited purpose," said Thornton. "However, there is nothing under the law" to prevent the profiles from being "kept, stored and resurrected for any lesser inquiry or any inquiry at all without their consent."

Detective Ottey said the Leicestershire police were well aware of the law's ambiguity and said that "every record in relation to {the volunteers} is being destroyed. It's treading on dangerous waters. We took blood on the understanding that it wouldn't be used for any other purpose than this one job. Besides, we haven't got facilities for storing everything." News of the genetic fingerprint has spread quickly. The idea of doing a genetic "sweep" for a murder suspect caught hold in Italy last week, when a popular television host suggested the use of the test to solve a murder in the village of Varese in Lombardy. A 21-year-old girl, a student of a Catholic fundamentalist movement, was knifed to death, and investigators interrogated several local priests before the trail grew cold. The town newspaper has already polled Varese's 90,000 inhabitants and found that 90 percent were ready to submit to the test.

"There's no difference between the use to which this information is put and fingerprints are put," said Ian Scott, a spokesman for the British Home Office. Guidelines, he said, already exist. "The same safeguards apply to DNA material as apply to other evidence gathered in the course of an investigation."

Robin Herman is a free-lance writer based in Paris.