An Elkridge man serving a life sentence for murder was formally charged yesterday with two more killings and is suspected of several others, possibly bringing closure to a series of unsolved homicides that frightened Howard County residents and baffled police almost two decades ago.

Vernon L. Clark, 43, was charged with first-degree murder in the death of Rebecca H. "Dolly" Davis, 70, whose throat was slit in Elkridge in 1980. Clark was also charged with first-degree murder in the death of Evelyn Dietrich, 68, of Catonsville, Md., who was found bludgeoned to death on her lawn in 1981.

It was a surprise phone call--and DNA testing unavailable at the time of the Davis and Dietrich homicides--that led to the charges in both cases, police said.

Last year, Howard County Detective Keith Fisher received a call from an unidentified woman who said she had new information in the death of Davis, Fisher said yesterday. The tip turned out to be wrong, but Fisher said the call spurred him to delve deeper into the case, in part because he had gone to church with Davis and his brother was a friend of hers.

Fisher said he knew that law enforcement authorities had suspected Clark in Davis's death, as well as Dietrich's, and he began reexamining evidence. He took a vaginal swab preserved for 18 years in the Davis case and sent it, along with a sample of Clark's DNA, to Cellmark Technologies in Germantown. The two samples matched, police said.

Fisher had been in touch for years with the Baltimore County detectives who had investigated Dietrich's homicide, and alerted them, police said. A DNA comparison was also done in that case, and Clark's sample matched one preserved in the Dietrich case, police said.

Law enforcement authorities had long suspected Clark in both deaths because the cases bore striking similarities to the 1989 shotgun death of Kathleen Gouldin, 23, of Elkridge.

In the Gouldin case, detectives were able to establish that Clark was at the scene of her homicide. And they knew that her killer had intercourse with Gouldin after her death. A DNA test--the first ever used in a Howard County prosecution--linked Clark to Gouldin, and he was convicted of first-degree murder and perverted practice. He was given a life sentence.

In the cases of both Davis and Dietrich, police said, the killer had intercourse with the victims after they died, but police could not establish any link to Clark until now. They were able to do so because of DNA testing that is more advanced than what was available in the Gouldin case a decade ago.

The Davis case was one of the biggest in Howard County. More than 10 Howard County detectives were assigned to it and followed leads as far as Texas, even employing a psychic.

Clark lived his entire life in Elkridge. He worked as an animal skinner for the Braun Carroll Co., an animal processor, until his arrest in 1990 in the Gouldin case. That arrest led police to reopen two other Elkridge murders that occurred in 1979, according to Howard County investigators.

Carvel Faulkner, 58, was shot to death and his wife, Sara, 56, had her throat slit. Clark had worked for C & S Faulkner Inc., a sanitation company that was run by the victims. He had also worked for Davis as a handyman and was Dietrich's gardener. Howard County detectives and state police investigators said they are conducting DNA tests to see if they can link Clark to the Faulkner murders. He is also a suspect in the 1984 beating death of Iva Myrtle Watson, 81, of Ellicott City, police said.

The arrest of Clark has evoked painful memories for Davis's family.

"It's good to know the crime has been solved," said her nephew James Davis. "Still, this brings back memories. . . we all have to work our way through."