The lawsuit to determine whether Dr. David Davoudlarian can be held responsible for the death of his wife, Susan, represents a judicial rarity: a civil, rather than a criminal, trial over an alleged slaying.

In addition to the case's often lurid testimony, the trial has attracted attention because it involves the efforts of the victim's family to press a case that the local prosecutor has declined to pursue in court.

In slaying cases, such lawsuits normally follow a criminal prosecution, particularly a conviction.

But in this case, lawyers for the estate of the slain woman filed a "wrongful death" complaint seeking civil damages from Davoudlarian after Fairfax County prosecutor Robert H. Horan Jr. concluded there was insufficient evidence on which to seek a grand jury indictment in her death.

"It's extremely rare," said Plato Cacheris, a veteran Washington-area criminal defense attorney who represents Davoudlarian. A spokesman for the Virginia attorney general's office said yesterday he knew of no precedent in the state.

The lawsuit has been a three-week courtroom airing of sordid and titillating details of the Davoudlarians' marriage, including differing accounts of whether it was troubled.

And because of the differing standards of Virginia civil and criminal law, the testimony has included much that would have been barred from a murder trial.

The state's wrongful death statute -- known as "the dead man's law" -- permits "statements, declarations and utterances" of the victim to be entered into evidence in the trial of a civil lawsuit, even though the same testimony would be excluded as hearsay in a criminal prosecution.

As a result, a jury verdict against Davoudlarian would not lead inevitably to a future prosecution on a murder charge because the standard of proof required in a criminal case is much higher than in civil proceedings.

Criminal prosecutors must prove guilt "beyond a reasonable doubt," while the plaintiff's lawyers in the Davoudlarian case, as Fairfax Circuit Judge Lewis Griffith instructed the jury yesterday, are required to show only that a "preponderance of the evidence" favors their side.

Preponderance, Griffith said, means "the greater weight" of the evidence. Cacheris, the doctor's lawyer, asked that the judge set the standard at "clear and convincing evidence," but Griffith refused.

"The jurors have to believe slightly more on one side than the other," said Steven Merril, a former Fairfax County prosecutor who is now in private practice. "You can have doubts and still find for the plaintiff" in a civil case, he said.

The exclusion of hearsay evidence in criminal trials is grounded in the constitutional right of an accused to face the accuser.

While the Davoudlarian case is rare, it is not unprecedented. In a 1981 case, an Ohio man sued his wife's insurance company claiming her $109,000 life insurance benefit after his wife was found strangled.

The woman's father countersued his son-in-law, alleging that the ex-husband was suspected of having killed his wife.

In the civil trial the father won the insurance. The son-in-law is scheduled to stand trial later this month in Ohio on a charge of giving perjured testimony about the death.

John Elam, a Columbus lawyer who represented the woman's father, said no murder charge has ever been presented to a grand jury for possible criminal proceedings in the case.