The rousing leadoff song in the musical “Kiss Me Kate” was “Another Op’nin’, Another Show.” The title of the Danny Pelosi murder trial should be “Another Big Case, Another Jailhouse Snitch.”

There are no fewer than six jailhouse informants willing to testify that Mr. Pelosi, a mediocre handyman and big-time hustler, admitted to them, in varying forms, that he had something to do with killing millionaire Ted Ammon.

Prison snitches are the lowest form of human species. They are often murderers, rapists, and child abusers – and they are notoriously unreliable. They are always looking for a ticket out of jail and will tell, embellish, or invent any story to get them through the gates.

Mr. Pelosi is on trial on murder charges in Riverhead, Long Island. In what reads like a pilot script for this year’s hottest TV show, “Desperate Housewives,” Mr. Pelosi, a smalltime hustler and electrician, landed a job working for Generosa Ammon, who was then married to Ted Ammon, a Manhattan financier worth some $80 million.

Generosa Ammon was attractive, restless, and rich, and Mr. Pelosi was charming and on the prowl. One thing led to another. By the spring of 2001, the Ammons were estranged and Mr. Pelosi had installed an elaborate surveillance system in the couple’s East Hampton mansion, where Ted Ammon was found beaten to death a few months later.

Generosa Ammon and Mr. Pelosi immediately became the prime suspects. That didn’t stop them from marrying a few months later, putting Mr. Pelosi in line for Ted Ammon’s fortune. But, love being what it is, the couple parted last year and Generosa Ammon left virtually her entire fortune to her children before she died of cancer a short time later.

That leaves Mr. Pelosi, 41, short of cash and alone to face murder charges. Prosecutors have mounds of circumstantial evidence, but nothing that directly ties Mr. Pelosi to the murder – except the jailhouse informants.

It may look like a slam-dunk now, in the early stages of the trial, but it’s not.

Mr. Ammon’s lawyers have up to six – count ’em six – six jailhouse snitches who say Mr. Pelosi confessed something.

Prosecutors say they have some 40 hours of tapes in which Mr. Pelosi, an apparent blabbermouth who is being held in the Suffolk County Jail, admitted to the slaying and plotted to intimidate a witness and tamper with a juror.

Mr. Pelosi’s lawyer, Gerald Shargel – they don’t come any better – says that the tapes are murky, at best, and that to believe them jurors will have to believe the snitches.

That is not an easy task. Without rock-solid corroboration, many juries have tossed out virtually everything jailhouse snitches – or criminal informants of any kind – say. They are unsavory, unlikable, and usually out of control.

The prime snitch against Mr. Pelosi – one Mr. Shargel is salivating to get on the witness stand – is Clayton Moultrie, a 39-year-old career criminal and longtime informant.

Moultrie says Mr. Pelosi told him he’d bashed Ted Ammon in the head, but Moultrie has major credibility problems. Before he came forward with his Pelosi tale, police had stopped using him as an informant last April because he was still committing crimes. Prosecutors bought his latest story anyway and sprung him from jail a few months ago. Guess what: Moultrie was arrested last week for holding up a convenience store in South Carolina with an icepick.

Jurors will probably end up hating – and distrusting – him, as they have done with informants in countless cases across the years.

Twenty-four years ago, a top-notch criminal lawyer named Miles Feinstein gave a textbook example of how to dismantle an informant.

The witness was a low-level mob henchman named Pat Pizzuto, who turned informant to get out of jail and wear a wire against his cohorts. Pizzuto gave a vivid account of a murder committed by a mob hit-man.

But then along came Mr. Feinstein, who began confronting Pizzuto with testimony he’d given when testifying for the defense in prior cases or before a grand jury in an earlier case.

Mr. Feinstein had a dozen big blue folders lined up on his desk. One-by-one, he asked Pizzuto about his testimony in each case.

“Were you lying then to protect your friend?” Mr. Feinstein asked.

“Yes,” Pizzuto replied.

“But you’re telling the truth now?”

“Yes.”

Mr. Feinstein placed the open folder on the witness stand next to Pizzuto and went to the next one.

Same questions; same answers. Pizzuto insisted he was lying then, to other jurors, but telling the truth now.

By the end of the cross-examination, the stack of folders towered over Pizzuto.

“So, it is your testimony that you lied to all those other jurors, but you’re telling these jurors the truth?” Mr. Feinstein concluded.

“Yes,” Pizzuto answered weakly.

The jury tossed out the murder charges and everything else that relied on Pizzuto’s testimony. A killer walked. Prosecutors are praying that won’t happen this time.