TRENTON — A federal grand jury in Trenton today returned an eight-count indictment charging Trenton Mayor Tony F. Mack, his brother, Ralphiel Mack, and Mayor Mack’s close associate, Joseph A. “JoJo” Giorgianni, with extortion, bribery and mail and wire fraud.

The U.S. Attorney’s office announced the indictment in a press release Thursday afternoon which detailed a scheme to accept $119,000 in bribes in exchange for Tony Mack assisting cooperating witnesses in developing an automated parking garage on city property.

“It was the object of the conspiracy to obtain money and other things of value, in exchange for the official action and influence of defendant Tony F. Mack,” the indictment said.

Giorgianni, who owns JoJo’s Steakhouse in Trenton, also is a convicted sex offender.

The investigation, which involved several cooperating witnesses, recordings and another coconspirator who worked with the FBI to unravel the scheme. The indictment also states the defendants used code phrases like “Uncle Remus” for corrupt payments, aliases like “Honey Fitz” for Tony Mack and Ralphiel Mack as an intermediary to shield Tony Mack from prosecution.

“The defendants went to great lengths to conceal their corrupt activity and keep Mayor Mack ‘safe’ from law enforcement,” the release said.

Up to the arrests of the three defendants in September, both Macks and Giorgianni had accepted some $54,000 in bribes of the planned $119,000 in payments, the indictment said. In exchange for those payments, the indictment said Mack would make the city offer the lot on East State Street to the developer for $100,000.

The indictment said the two people Giorgianni approached with the scheme were cooperating with the FBI. Sources said the first cooperating witness is Lemuel H. Blackburn Jr., a former Trenton-area attorney who was disbarred in 2002 after admitting he could not successfully defend pending disciplinary charges.

The FBI’s complaint alleges CW-1 met with Giorgianni on Sept. 14, 2010, at JoJo’s Steakhouse to begin discussions on the alleged extortion scheme. “CW-1 has cooperated with law enforcement in the hopes of obtaining a more favorable outcome with respect to criminal charges,” according to the FBI. CW-1 presented himself to Giorgianni as a consultant for CW-2.

CW-2, according to sources, is North Bergen developer firm Seymour Building. CW-2 was proposing to build a parking garage on East State Street in Trenton. In reality, there was no parking garage plan, just a group of federal agents and the cooperating witnesses wiretapping the mayor and Giorgianni.

In order to keep Tony Mack out of legal trouble, the conspirators used various “buffers” who included, Giorgianni, Ralphiel Mack and CC-1, who sources have identified as Charles Hall III, is a recreation department employee, according to the indictment.

They limited their conversations over the phone to frustrate electronic surveillance and used code phrases such as “Uncle Remus” to refer to corrupt payments, according to the indictment. The coconspirators in the case also met outside of City Hall, at JoJo’s Steakhouse, Giorgianni’s house, Giorgianni’s Clubhouse and Atlantic City restaurants.

Giorgianni was also indicted with scheming to steer a power washing contract to a city vendor in exchange for a kickback to a city employee. That scheme involved CC-1 (Hall) and another unnamed co-conspirator who the indictment identifies as running JoJo’s Steakhouse in Trenton.

The indictment said Giorgianni extorted money from the owner of a car detailing business in order to give it to Hall, in exchange for that unnamed individual getting a contract with the city.

Giorgianni had the company owner inflate the invoice by more than $1,000, which was left with CC-2 at JoJo’s Steakhouse. Giorgianni then passed the money to Hall in Atlantic City.

Giorgianni is involved in a second case regarding an oxycodone distribution conspiracy, that also involved Hall, which is on a continuance and might be indicted before February.