By John BurtonFREEHOLD – A Monmouth County grand jury has handed down indictments against 20 individuals who, law enforcement charge, operated an extensive drug and firearms trafficking operation.The defendants, who face a wide array of charges, were among 40 arrested last summer following an investigation that began in fall 2010, according to the Monmouth County Prosecutor’s Office.Authorities have named Anthony Stevenson, also known as “Nygee,” a 43-year-old Long Branch resident, as the alleged ringleader.The operation was allegedly based in Long Branch, authorities said. The eight-month investigation was initiated after the prosecutor’s Narcotics and Criminal Enterprises unit received information about the ring’s operation.The prosecutor’s office charges that during the investigation Stevenson either sold or directed one of his underlings to sell heroin to customers who turned out to be undercover officers.Authorities alleged the officers bought upward of 38 bricks of heroin from Stevenson or his associates. A brick, law enforcement officials said, contains 50 small glassine bags of the illegal drug.Along with heroin, Stevenson and his associates are also alleged to have sold cocaine to officers, authorities said.The investigation revealed Stevenson relied on different suppliers operating in the Newark area, policesaid. The most significant amount allegedly came from Uwenzen Jenkins, 40, West Orange.Two of Stevenson’s associates from Asbury Park, who were under surveillance by officers, were stopped by the police in Tinton Falls after meeting with Jenkins on July 1, and found to be in possession of 40 bricks of heroin.The following month, Stevenson and another associate were stopped and arrested when they were allegedly in possession of 50 heroin bricks.Along with the narcotics, law enforcement charged that Stevenson brokered the sale of illegal guns. In one case a Stevenson associate sold a handgun in a Long Branch restaurant owned by Stevenson. Another sale allegedly occurred when Stevenson sold two assault rifles to undercover officers in the parking lot of a West Long Branch gas station, police said.Two of Stevenson’s associates, Walter Taylor III, 35, Long Branch, and Latief Forbes, 29 (no residence provided), are alleged to have operated a drug production facility in Freehold, according to the prosecutor’s office.Among the list of charges Stevenson is facing include: first degree leader of narcotics trafficking; second degree racketeering conspiracy; and numerous drug and illegal firearms possession offenses.The alleged co-conspirators are from Long Branch, Asbury Park, Neptune, Red Bank, West Orange, and two from South Carolina, who are former Long Branch residents.Stevenson’s bail was set at $2 million, cash only and no 10 percent option.He is being held at the Monmouth Correctional Institution, Freehold, pending a prosecutor-requested bond source hearing to determine whether the source of the bond is from criminal activity, First Assistant Prosecutor Christopher Gramiccioni said.