RICHMOND, Va. (AP) _ A scientific test that has found growing use in court to identify crime suspects through genetic patterns in body cells will be challenged this week in the appeal of a man who faces four death sentences.

Timothy W. Spencer, 26, a former resident of a Richmond halfway house, was the first defendant in a serial-murder case in the nation to be confronted with so-called ''DNA fingerprinting'' evidence at his trials.

DNA, deoxyribonucleic acid, is the basic genetic material found in each cell of the human body and forms the blueprint for each individual. Everyone's DNA pattern is believed to be unique, with the exception of identical twins.

Spencer was convicted and sentenced to death in separate trials last year for the rape-murders of Susan M. Tucker, 44, of Arlington, and Debbie Dudley Davis, 35, of Richmond.

This year, he was convicted and sentenced to die in two other cases, the rape-murders of Dr. Susan Elizabeth Hellams, 32, of Richmond, and Diane Cho, 15, of Chesterfield County.

All four victims were bound and strangled by an assailant who broke into their homes through a window.

In each case, DNA from a sample of semen found at the crime scene was compared to DNA patterns in Spencer's blood cells. The results linked him to the murders.

The genetic evidence was challenged by defense lawyers at Spencer's trials, but the judges allowed the test results in each case.

Although the DNA test, developed in England, is relatively new, Bert Rohrer, a spokesman for Attorney General Mary Sue Terry, said courts are likely to uphold such a test if it is determined to be reliable.

At Spencer's trial for the Davis murder, experts testified that the DNA patterns found in the defendant's blood and in the semen sample found with the victim matched. The odds of finding such a match randomly was one in 705 million, they testified.

But Jeffery L. Everhart, a Richmond attorney who represented Spencer in the Davis killing, argued that the DNA procedure is too unproved to be relied upon exclusively, as it was in that and the other cases, to put the defendant at the scene of the crime.

Defense lawyers argued that the procedure's reliability may come into question in future research on forensic evidence.

On Thursday, the Virginia Supreme Court will hear challenges to the DNA evidence and other issues that arose in Spencer's trials for the Tucker and Davis murders.

The appeals went to the high court on automatic review, a standard procedure when anyone is sentenced to execution in Virginia. Spencer's appeals in the Hellams and Cho murders will be heard later.

Spencer also was linked to a fifth murder. But Arlington County Commonwealth's Attorney Helen Fahey said Spencer would not be charged in that slaying because DNA testing of the aging evidence was inconclusive.

Another man, David Vasquez, was sentenced to a 35-year prison term for that killing after pleading guilty to first-degree murder but was pardoned by Gov. Gerald L. Baliles when new evidence came to light.