If the ongoing hearing is any indication, next month’s long awaited trial of a former FBI supervisor, R. Lindley DeVecchio, is going to be a blockbuster event.

Last week, for example, it was disclosed that a key prosecution witness would testify that Mr. DeVecchio served as a lookout/protector for a band of bank burglars headed by the late Gregory Scarpa Sr., a murderous mobster who was also an informer for the ex-FBI agent.

The witness, Scarpa’s son, Gregory Jr., says he was a member of his father’s bank burglary crew and claims to have seen Mr. DeVecchio during several bank jobs, according to the testimony of Thomas Dades, a retired investigator for the Brooklyn district attorney, Charles Hynes.

Mr. Dades is one of several investigators and prosecutors who testified before Justice Gustin Reichbach in state Supreme Court in Brooklyn in an effort to rebut defense allegations that the Brooklyn district attorney’s office improperly used testimony for which Mr. DeVecchio had received immunity in order to obtain a murder indictment against the retired agent.

At the hearing, Mr. Dades and others who were involved in the district attorney’s investigation testified that they did not use, directly or indirectly, any of the immunized testimony that Mr. DeVecchio gave on three occasions during the 1990s.

They did get an earful from Scarpa’s son, Mr. Dades testified. The retired NYPD detective said Scarpa Jr. told members of the prosecution team that during the 1980s, Mr. DeVecchio was on the scene as the father-son gangster team, along with other Colombo mobsters and associates, “were doing, like, bypass burglaries of banks … not armed bank robberies while the bank was opened.”

Scarpa Jr., who is currently serving 40 years for murder conspiracy, drug dealing, and other charges, said his father had told him that Mr. DeVecchio “was always there,” Mr. Dades testified, adding that “once or twice” the younger Scarpa spotted Mr. DeVecchio “present at the banks to interfere in case the police came.”

Judge Reichbach blocked follow-up defense queries into that subject as beyond the scope of the hearing, forcing Mr. DeVecchio’s attorneys, and Gang Land, to wait until after trial begins September 10 to learn further details about the ex-agent’s alleged nighttime exploits.

Mr. DeVecchio’s lawyers, who have previously blasted the murder charges against the decorated ex-agent as “ludicrous” and “beyond belief,” did manage to pry some new insight about the prosecution’s evidence from Mr. Dades and other witnesses during the hearing.

Under questioning by a defense attorney, Mark Bederow, Mr. Dades testified that Scarpa Jr. told prosecutors he maintained a ledger in which he recorded payments that his father had given to Mr. DeVecchio — whose code name between the father and son was “D” — for favors the agent provided to the Scarpa crew.

Scarpa Jr. told prosecutors that he never met or spoke to Mr. DeVecchio but said that he accompanied his father to clandestine meetings he had with the G-man, Mr. Dades testified.

“He said that on numerous occasions they would meet him on a road in Jersey, Route 9, where Mr. DeVecchio would be in a car. Greg Senior would leave the car, with Greg Junior in the car, and get into the car and say that was ‘D’ that he was meeting,” Mr. Dades said.

During a testy exchange with another witness, Mr. Bederow learned that the prosecution contends that Mr. DeVecchio used a “go-between” to threaten the elder Scarpa’s longtime companion, Linda Schiro, from cooperating with FBI officials during a previous internal investigation by the bureau into corruption allegations against Mr. DeVecchio.

“Your client instructed Linda Schiro to tell those individuals to go f— themselves,” Assistant District Attorney Michael Vecchione, who will serve as the lead prosecutor at the trial, testified. Mr. Vecchione, the chief of the Brooklyn district attorney’s Rackets Bureau, said the confrontations between Mr. DeVecchio and the “go-between,” John Baran, took place in front of the FBI building at 26 Federal Plaza.

According to court records, Ms. Schiro, a linchpin of the prosecution’s case, told the grand jury that indicted Mr. DeVecchio that she was present for many meetings Scarpa Sr. and Mr. DeVecchio had had over the years and had overheard them discuss four murders between 1984 and 1992.

Mr. Dades, who solved the 1995 murder of Ms. Schiro’s son Joseph, maintained a friendly relationship with her and convinced her to cooperate with Mr. Hynes’s office’s probe in 2005, according to testimony at the hearing.

Scarpa Jr., 56, began talking with the Brooklyn district attorney’s office last year after a self-styled forensic analyst, Angela Clemente, trumpeted him as a credible witness who could aid the prosecution, according to evidence that emerged at the hearing.

Ms. Clemente, who followed Mr. Dades on the witness stand, said she met Scarpa Jr. in 2003 while she was trying to uncover evidence that mobster Joseph Russo was wrongly convicted of two murders during the bloody Colombo war.

Under questioning by Mr. Bederow, Ms. Clemente, whose attorney also represented the late Russo, conceded that she had read Mr. DeVecchio’s immunized testimony. But she steadfastly denied passing it along to a prosecutor, even when confronted with emails in which she did just that. (Prosecutors who saw transcripts of the testimony say they never read them).

In an effort to tarnish her credibility, Mr. Bederow zeroed in on Ms. Clemente’s ties to — and her financial arrangements with — Mr. Hynes’s office, the Russo family, and relatives of two other Colombo wise guys involved in the DeVecchio saga.

Ms. Clemente admitted to getting hotel and travel expenses from the Brooklyn district attorney’s office and the Russo family, but didn’t say how much. She also testified that she is working on a contingency fee basis for family members of a late Colombo mobster, Nicholas “Nicky Black” Grancio, who have a wrongful death lawsuit pending against Mr. DeVecchio.

Judge Reichbach gently chided Ms. Clemente for waiting until the morning of her appearance to give Mr. DeVecchio’s lawyers thousands of pages of documents that she had been ordered to turn over to the defense. The hearing ends next week with the testimony of Ms. Clemente and Sandra Harmon, who had once planned to write a book with Ms. Schiro and is now working on one with Scarpa Jr.

THE WORDS OF THE RING

Scarpa Jr. and Ms. Schiro have each told prosecutors that during the early 1980s, Scarpa Sr. used Mr. DeVecchio to return a stolen World Series ring belonging to a Yankees Hall of Fame pitcher, Whitey Ford, Gang Land has learned.

“Greg was a big Yankee fan, and when they found a ring belonging to Ford in the loot from a Queens bank burglary, he reached out to DeVecchio and he arranged to have another agent return the ring,” a source familiar with the accounts provided by Scarpa Jr. and Ms. Schiro said.

Knowledgeable sources say prosecutors intend to have both witnesses relate the fascinating story at Mr. DeVecchio’s trial as evidence of the close relationship between the ex-agent and Scarpa Sr.

In a confusing, disjointed witness stand account of the caper that was reported in the New York Post, Ms. Clemente testified that the incident convinced her that the internal FBI probe of Mr. DeVecchio was a “faulty” endeavor that was doomed to fail.

Mr. Bederow, who is sure to question Ms. Clemente about the episode next week, declined to comment about the reputed return of Mr. Ford’s stolen World Series ring by his client.

Gang Land contacted the 78-year-old erstwhile Yankee lefty to give him the final say in this week’s column. Sounding as spry as he did when he was winning 236 games and losing only 106 as the “Chairman of the Board” in the 1950s and ’60s, Mr. Ford said more than one ring was stolen, and he never got any back. The owner of the Yankees, George Steinbrenner, had had replacements made for him, he said.

“My rings were stolen from the bank, from the safety deposit box,” Mr. Ford said. “I don’t recall the year, but we never got them back. The Yankees had a day for me at the Stadium and Mr. Steinbrenner had the rings remade for me.”

This column and other news of organized crime will be available today at ganglandnews.com.