Police found the woman with a rope tied around her neck and her wrists cinched up high behind her back. She had been raped and strangled in her bed.
Her 1987 murder closely matched two others discovered in Virginia in the previous six weeks, and police believed they were dealing with one killer. But there were no witnesses and no usable fingerprints at the crime scenes, only small amounts of seminal fluid.
By using genetic -- or DNA -- profiling techniques developed just two years before in England, a private laboratory confirmed that the semen samples from all three attacks were identical.
But that was not enough to identify the killer.
In the end, it was conventional detective work that led police to Timothy Spencer, a convicted burglar living in a halfway house just blocks from two of the murders.
DNA tests then matched Spencer's blood with semen samples from all three crimes. He later became the first person in Virginia to be convicted with the help of DNA profiling.
But what Virginia really needed was a DNA "bank," a sort of genetic mug file of known criminals, against which body tissues and fluids left at crime scenes could be compared. And it would have to be fast -- computerized, just as fingerprint searches are now.
Had a DNA bank been available in Virginia after Spencer's first murder, two lives might have been saved.
Today, Virginia's Division of Consolidated Laboratory Services is developing a DNA bank that probably will be the first ever used strictly for law enforcement.
The project is backed by a legislative mandate and a U.S. District Court judge, who in March rejected convicts' claims that the testing violated constitutional rights to privacy and protection from unreasonable searches. The case is being appealed.
Blood samples from more than 30,000 convicted Virginia felons have already been collected and stored for profiling. The profile data eventually will be digitized and stored in a computer.
Paul B. Ferrara, director of the state's Division of Forensic Science, said his lab has begun profiling DNA samples and hopes to have the DNA profiles of as many as 3,000 felons in the computer by July 1, 1992.
"Then the next goal will be to start running DNA [searches] on those cases where police do not have a suspect," he said. The first searches will be limited to sex offenders.
At least 10 more states have passed legislation establishing their own DNA banks, despite concern among civil libertarians. A dozen more states are considering the idea.
In Washington, the FBI -- which already performs DNA profiles for police agencies across the country -- is working to standardize the process. It also is establishing a computerized National DNA Index. The computer system will allow police agencies to compare DNA profiles from crime scene evidence with DNA profiles from offenders convicted previously in other states.
Virginia is to install the FBI software for testing beginning next month.
"This will be a powerful tool for forensic science," Ferrara said, "and it's going to come pretty rapidly."
The prospect of a nationwide DNA data bank system for identifying suspects directly from crime scene evidence delights law enforcement officials, who say high rates of recidivism demand it.
A Bureau of Justice Statistics study of state prisoners found that 62 percent of those released in 1983 had been rearrested within three years; 41 percent returned to prison.
Advocates compare DNA banking with the expanding Automated Fingerprint Identification System, which in the past decade has digitized and stored the fingerprints of 6 million criminals for searches by police agencies looking for matches with crime scene evidence.
"In 10 years, tens of thousands of crimes have been solved [through AFIS] that wouldn't have been before because police didn't have suspects," Ferrara said. "The DNA bank is just an extension of that concept."
But civil libertarians see DNA banks as a potential threat to privacy and to Fourth Amendment protections against unreasonable searches.
"Since there can be no probable cause to believe someone committed a crime in the future, we're very concerned about the coercive nature of taking the sample," said Janlori Goldman, director of the American Civil Liberties Union's privacy and technology project.
The ACLU also wants to be sure that DNA profiles are not used as the sole basis for an arrest, and that they are done accurately.
"It's an emerging technology, and there are lots of questions to be answered," she said. "We are pushing hard for strict, uniform standards."
There is also a debate raging about how conclusive the tests really are.
Experts typically put the odds of two people having matching DNA profiles in the range of tens or hundreds of millions to one. But Goldman insists DNA profiling "cannot provide an exact match; it can only show a percent probability of a match."
Then there are privacy issues.