Thomas Gioeli, Reputed Former Acting Boss of the Columbos, on Trial for Alledged Role in Killing of Police Officer and 5 Others

The off-duty police officer was ambushed by gunmen, and left to die in the street outside his home in Brooklyn.

For two other men, the end came farther from home: they were killed separately in the basement of a man they had trusted, prosecutors say. One was a mob associate who wanted out of the life; he was shot once in the back of the head, never to be seen again. The other was an underboss who apparently had accumulated too much clout for comfort; his body was not found for nearly a decade.

Those killings and three others, all from the 1990s, were described on Monday in the opening statement of Cristina M. Posa, a federal prosecutor. They are at the heart of the prosecution of Thomas Gioeli, whom officials called the former acting boss of the Colombo crime family, and Dino Saracino, who the authorities say was one of his hit men, on murder and racketeering charges in Federal District Court in Brooklyn.

Ms. Posa said the murder crew was methodical in its preparations, trailing potential victims for days to determine their habits, luring them to the places where they would be killed, disposing of evidence and disposing of bodies. “As professional killers, that was their specialty — committing murder and getting away with it — until today,” Ms. Posa told the jurors, many of whom said during jury selection that they had known little of the ways of the mob.

The prosecution plans to call cooperating witnesses who will describe how the killings were carried out.

Of the six killings, the one shrouded in the most mystery was that of the police officer, Ralph C. Dols, 28, in 1997.

Officer Dols had married a woman, Kim T. Kennaugh, who had been previously married to three men associated with the Colombo crime family. One of them, Enrico Carrini, was killed in 1987; the most recent former husband was Joel Cacace, also known as Joe Waverly, described by officials as a consigliere, or top mob adviser. Mr. Cacace is awaiting trial on murder and other charges.

Federal prosecutors have accused Mr. Cacace of ordering Mr. Saracino and others to kill Officer Dols because it was embarrassing that Ms. Kennaugh would leave a powerful mobster for someone in law enforcement. Mr. Saracino, known as Little Dino, and Mr. Gioeli, known as Tommy Shots, were among those charged with the murder of the underboss, William (Wild Bill) Cutolo Sr., who was a union official. His body was found on Long Island in 2008 after the authorities were tipped off by an informer.

Mr. Gioeli’s lawyer, Carl J. Herman, said in his opening remarks on Monday that the prosecution had built its case based on the work of a desperate federal agent who relied on cooperating witnesses who had reason to lie.

“The F.B.I. since the mid-’90s has been attempting to gather evidence on Gioeli by surveillance,” Mr. Herman said. “Sometimes they get a little desperate, your government, and that’s what happened in this case.”

Samuel M. Braverman, a lawyer for Mr. Saracino, said there was no physical evidence that the homicides even happened. He said the prosecution could only present the testimony of sociopaths who could not be trusted.

“I’m not here to tell you Dino is a choirboy,” Mr. Braverman said of Mr. Saracino. “He isn’t. I’m not here to tell you he didn’t commit the murders because he’s a nice guy. I’m telling you he didn’t commit the murders because he didn’t commit the murders.”

This list of people who were killed for crossing the Colombo family is long. In 1991, Frank Marasa, known as Chestnut, was killed to avenge the death of a Colombo family member, prosecutors said. A year later, John Minerva took the wrong side in a war that split the Colombo family. He was killed in his car with another man, Michael Imbergamo, prosecutors said.

In 1995, Richard Greaves wanted to leave the Colombo mob, so he had to be eliminated, prosecutors said. In 1997, Officer Dols was killed. Mr. Cutolo’s killing was in 1999.

Katherine Kelley, an F.B.I. agent, said she was present at the wooded lot where Mr. Cutolo’s body was finally discovered; the toes of his shoes protruded above ground. She led a team of excavators, who, with small tools, removed the body, which she said was covered with bits of lime, its blackened and skeletal limbs hogtied behind its back.

Judge Brian M. Cogan ordered a short break during Ms. Kelley’s testimony. Mr. Gioeli, looking avuncular in a navy shirt, a tan sweater vest and a tie, smiled and waved to friends and family in the audience. He blew them kisses.

Mr. Saracino, wearing a crisp blue shirt and tie, his head shaved, offered no expression. He and Mr. Gioeli face life in prison if convicted.

Thanks to Mosi Secret