ROAD TOWN, British Virgin Islands — Three days after telling police that cellmate William Labrador confessed to drowning Lois McMillen, Jeffrey Plante wished Barbara Labrador a happy Mother's Day and urged her to remain optimistic about her son's release.

"You are aware that I am helping William as much as possible. I hope it will all work out soon," Plante, a 59-year-old Texan, wrote the Southampton, N.Y., woman from a prison here on May 14, 2000.

But despite the claim that he was helping William Labrador, Plante just three days earlier told police that Labrador confessed to killing McMillen during an argument over money and because she was "no good."

On the stand for a second day Wednesday, at the request of the defense Plante read the letter he wrote to Barbara Labrador. Lawyers for William Labrador, 37, and three co-defendants charged with killing McMillen are trying to convince the jury that Plante is an opportunist who will do or say anything to save his own hide.

Flustered but not broken by a barrage of questions attacking his credibility, Plante leaned on a railing as he insisted again that he was telling the truth about Labrador's alleged prison confession just before Good Friday last year.

"I assure you that what I told you Mr. Labrador said is the God's honest truth," Plante testified, eliciting groans from the relatives of Labrador and co-defendants Michael Spicer, Evan George and Alexander Benedetto.

But there was laughter too. Even Justice Kenneth Benjamin smiled when Plante blurted out that six of his 10 marriages were "proxies" born out of convenience.

"I never even kissed those people. It was strictly done by paperwork and done for business purposes," said Plante, whom the jury has already heard is a convicted swindler who owes Texas 33 years for violating parole in a major theft case.

Watching Plante answer questions from Labrador's lawyer, Richard Hector, was like listening to Budd Abbott and Lou Costello perform their famous "Who's On First?" skit.

For example, Plante answered "no, sir" when Hector asked if he accepted a check for $4,700 from the British Virgin Islands government after testifying against Labrador last year. Pressed, Plante said the amount was actually $4,600. At other times, Plante answered no when asked about actions by his probation officer, but yes when Hector substituted the correct title of parole officer.

As amusing as some of Wednesday's testimony was for the gallery and seven women and two men on the jury, Russell and Josephine McMillen, the victim's parents, were stonefaced. The judge also was growing tired of the protracted line of questioning designed to attack the credibility of Plante, the prosecution's star witness.

When Hector pressed Plante about his parole status for more than 40 minutes, Benjamin interrupted the lawyer with a warning to move on.

"Mr. Hector, this trial is about murder. If you want to have a trial about parole, I suggest you convene another case," Benjamin said sternly.

Hector, in response, brought the questioning back to the issue of the time Plante spent with Labrador inside Her Majesty's Prison, where the defendants have been held without bail since being charged with the Jan. 15, 2000, killing of Lois McMillen.

Hector got Plante to say that he was considering loaning $25,000 to Labrador's defense, but later proved that Plante had put the legal wheels in motion for the loan, which was never finalized. Plante offered that he felt no choice but to loan money to Labrador, whom Plante said had a "volatile temper" and long knife while in prison.

Labrador shook his head as Plante described the knife, which Plante claimed was supplied by a fellow inmate. Barbara Labrador also shook her head and wrote notes furiously as Plante testified. Seated next to her, defense legal advisor Michael Griffith of New York whispered that prosecutor Terrence Williams should never have called someone who is so clearly a liar to the stand.

"It is shameful that the prosecution put this guy on the stand," Griffith said.

Williams said through a spokesperson that the prosecution will not comment until the trial concludes; this winter, Williams said in a written statement that the "crucible of the trial process" will determine Plante's credibility.

Just before lunch, Hector started a new front of attack on Plante's credibility. He asked Plante whether he wrote a letter to a Texas judge, a letter in which someone claiming to be Jeffrey Plante claimed that he was an Air Force pilot in Vietnam, won two air combat medals and spent 16 months in a Vietnam POW camp. Plante denied that he wrote the letter and said he never served in the armed forces.

After the lunch break, Hector accused Plante of making Labrador's confession up. He called him a thief and suggested that Plante would do anything to avoid extradition to Texas.

"You'd do anything, would you not, to save your own skin?" Hector asked.

Plante replied, "Mr. Hector, I have been guilty of some things in the past but I would never kill someone."

"You wouldn't kill someone, but you'd rob them to death," Hector said.

Plante then said he had met Lois McMillen on a nearby island in September 1999 and spoke to her for about 30 minutes. "She seemed like a nice young woman," he said.