DNA from a drinking glass in the home where two lawyers were shot to death in May may be used against Scotland E. Williams when he is tried in the slayings next week, an Anne Arundel circuit judge ruled yesterday.
Judge Eugene M. Lerner ruled that the kind of test used on DNA scraped from one of three drinking glasses taken by police from the victims' weekend home is acceptable enough to scientists that it may be used in Mr. Williams' trial.
Mr. Williams, 31, of the 800 block of Bradford Ave. in Arnold could be sentenced to death if convicted in the killing of Jose E. Trias, 49, and his wife, Julie Noel Gilbert, 48, both Washington lawyers.
Jury selection is expected to begin tomorrow.
Police said Mr. Williams was photographed by video cameras as he used Mr. Trias' bank card at two Glen Burnie banks a short time after the slayings and that he was carrying Ms. Gilbert's watch when he was arrested outside his home May 19, three days after the deaths.
Yesterday's decision will help prosecutors argue Mr. Williams was in the Winchester on the Severn house where the couple were shot to death in their bed.
"I think it's very significant," Assistant State's Attorney Cynthia M. Ferris said after the ruling.
Ms. Ferris said scientific testimony will show that Mr. Williams is one in 890 people in the black population with the same type of DNA that was scraped from the glass, which was found in the kitchen.
The two-day hearing was requested by Mr. Williams' lawyers, who argued that the DNA tests used -- called polymerase chain reaction, or PCR -- were too experimental and unreliable to be used in court.
Prosecutors said they used PCR tests on the drinking glass because the DNA sample found was too small to permit the use of the more widely known restriction fragment length polymorphism DNA test, which is admissible in court under state statutes.
In his ruling, Judge Lerner said he was convinced of the PCR test's reliability because of the standards and methods used by Cellmark Diagnostic Laboratories, the Germantown lab that conducted the DNA tests.
Cellmark is also being used by prosecutors in the O. J. Simpson murder trial.
Judge Lerner also said he was persuaded by the fact that of the 13 criminal cases in which PCR tests have been challenged in appellate courts in other states, its use has been permitted in 12.
"It seems to me that it's becoming a consensus in the court system that it's a reliable method," Judge Lerner said.
Maryland's appellate courts have yet to rule on the use of PCR tests, said State's Attorney Frank R. Weathersbee, who is prosecuting the case with Ms. Ferris.
Ms. Ferris told Judge Lerner that the evidence will show Mr. Williams took a drink of water from the victims' kitchen faucet before or after the slayings and left the faucet running when he fled the house.
The water was still running when police were called, she said.
She said she also hopes to use as evidence footprints found in the kitchen, which she said match Mr. Williams' shoe size.
"It's going to be the state's position that he was in that kitchen," she said.
According to charging documents, the home of Ms. Gilbert and Mr. Trias, in the 1600 block of Father Urban Lane, was broken into through a sliding glass door.
Mr. Trias was a legal scholar who worked for the Hughes Institute, the largest private philanthropy in the country, with $7 billion in assets. It finances basic medical research.
Ms. Gilbert was a tax attorney dealing with tax-exempt organizations. She worked at an international law firm in Washington.
The trial is expected to begin Monday and continue for two weeks.