An Alexandra jury's decision to free prosecutor William L. Cowhig of bribery charges turned on the jury's doubts about the credibility of a key prosecution witness's testimony and the prosecutor's failure to show that Cowhig lived beyond his means, a juror said yesterday.

"They had to prove the [the case against Cowhig] beyond a reasonable doubt and each link in that chain had to stand up to that test," said one juthe links fell apart after all that scrutiny."

The juror said a major problem in the prosecution case was Dirgham Salahi, the private school administrator who told of giving Cowhig $32,00 to protect the school's bingo games. Salahi, who had been granted immunity from prosecution for his testimony, was "not believable," the juror said.

The jury was troubled that Salahi could offer his "word only" on the alleged bribes and that the special prosecutor failed to document his claim that Cowhig had lived beyond his $42,500 public salary, the juror said. A woman on the jury pointed out early in the 13 hours of deliberations that Virginia State Police investigator Coy Ivy had failed to figure in Cowhig's savings account at a City Hall credit union into his analysis of Cowhig's finances, jury sources said.

Other jurors found it hard to believe that Cowhig would take the risk of going to a bingo hall himself to collect a bribe as Salahi claimed. Such a step was too "dumb" to be plausible, according to other sources.

For most of their 13 hours, the jurors were split five to five with two undecided, according to a juror.

Those favoring the guilty verdict pointed to what they said were "income discrepancies" in Cowhig's financial records, according to jury sources. Others said they believed the prosecution's claim that Cowhig "clearly needed money" to support the small resort hotel he owned in the Bahamas.

For the most part the juror's discussions were "sober" but sometimes tense. "You put 12 people in a room for that period of time and you're going to have some flare-ups," said the juror.

When the jury adjourned at 2:50 a.m. yesterday, there were still at least three jurors who favored a guilty verdict or were still undecided, according to sources. But within half an hour after they returned yesterday afternoon they had decided to acquit Cowhig.

"I guess the jury just needed to sleep on it," said the juror.