Federal prosecutors in Dallas have filed a racketeering conspiracy case against 14 members of the Texas Syndicate prison gang, alleging that they are responsible for at least a dozen murders and more than a decade of drug trafficking and other criminal activity.

Ten of those indicted were already in custody on other charges, and four more were arrested in recent days before the indictment was unsealed. But the use of Racketeer Influenced and Corrupt Organizations, or RICO, statutes in this case breaks new ground locally, U.S. Attorney Richard Roper said Tuesday.

"What we're doing with this indictment is we're using the criminal statutes that were designed to take down the traditional Mafia, La Cosa Nostra, violent gangs in the northeast part of the United States," he said. "We're using this for the first time in North Texas to try to dismantle a violent prison gang."

Ten of the murders in the indictment occurred in the Dallas area, and two were in South Texas. One occurred in 2003 at the now-closed Club Suavemente, the notorious club on West Mockingbird Lane that was the scene of several parking lot killings in recent years.

Like the Mafia, the Syndicate is secretive, hierarchical and not above slaying one of its members if he is perceived to be out of line, prosecutors allege. Membership is for life, and Syndicate members who are released from prison are expected to do the bidding of those on the inside.

Syndicate members often partner with relatives in common street gangs in narcotics activity or violence, authorities said.

Although the Syndicate doesn't engage in random violence, it is still a danger to the city, said Lt. Santos Cadena, head of the Dallas police gang unit.

"Any time you talk about the drug trade, you're going to have violence and firearms involved," Lt. Cadena said. "That's where you are going to see a threat to the city. Who's to say where they are going to conduct a drug deal? It could be an apartment, in a parking lot, you never know when things will go wrong and people other than the targets could get hurt."

Leadership of the group, Texas' largest prison gang, includes paramilitary titles such as lieutenant and sergeant, who are led by chairmen, known as sillons. Regular members are called soldiers. New members are prospectos.

Arrested in the last two weeks in the Dallas area are Marco Medina (a.k.a. Pantera), a lieutenant in Dallas; David Gutierrez, a soldier in Dallas and Houston; and Walter Lopez (a.k.a. Big Homie), a soldier in Dallas. The last defendant to be arrested was Sixto Salinas Jr., a soldier in the Rio Grande Valley and Dallas who was picked up in Laredo on Friday.

Other co-defendants include Juan Antonio Vasquez (a.k.a. Juanillo), a sillon in the Rio Grande Valley; Hector Manuel Ayala (a.k.a. Homicide), a lieutenant in Dallas; Javier Soliz, (a.k.a. Payaso), a sergeant in Dallas; Primitivo Ybarra (a.k.a. Munch), a soldier in Dallas; Daniel Arredondo (a.k.a. Weasel), a soldier in Dallas and San Antonio; Arnulfo Rodriguez (a.k.a. Gangster), a soldier in Dallas; Emilio Noyola (a.k.a. Mili), a prospecto in Dallas; Daniel Garcia (a.k.a. D), a prospecto in Dallas; and Edwin Barron (a.k.a. Beaver), a prospecto in Dallas.

Prosecutors allege that the group was led by Roy Arredondo, the Dallas sillon who was implicated in four murders from 1999 to late 2004. In February, he was sentenced to 40 years in prison in a major drug distribution conspiracy case that included 20 other Syndicate members, all accused of moving cocaine, methamphetamine and marijuana to places such as Austin and Lamesa, Texas, as well as Illinois and Tennessee.

Half of the Syndicate members in that drug case received sentences of 14 years or more.

Sentences under the current RICO case could be up to life in prison. There is no parole in the federal system.

The current indictment alleges that the RICO conspiracy began in North Texas in the mid-1990s. Prosecutors say the defendants conspired to participate in a violent enterprise responsible for murders, attempted murders, conspiracies to commit murder, robbery and drug trafficking.

Between October 1999 and September 2004, prosecutors allege, the defendants committed 12 murders – two in the Rio Grande Valley and the others in the Dallas area. The victims include:

•Ernesto Ramos Galvan, 33, who was found Oct. 3, 1999, shot to death in an alley near his home in the 900 block of Singleton Boulevard. The indictment says that on Oct. 2, three of the defendants picked him up and rode around drinking with him and at some point shot and dumped him.

•Maximino Sanchez, 34, a rival gang member, who was shot execution-style in the bathroom of the Dallas Unique club in the 2300 block of Mountain Lake Road on Jan. 23, 2000.

•Lorenzo Figueroa, who was shot in April 2000 in the Dallas area after he was given drugs by Syndicate members on consignment and refused to pay for them. He later died.

•Peter Paul Pecina, 39, of Dallas, who was shot to death and his body stuffed in the trunk of a car Oct. 28, 2001. The car was driven to a secluded area in the 2400 block of East Sixth Street in Irving and set on fire.

•Hector Camacho, who was shot Dec. 26, 2001, at his home in South Texas by Syndicate members because he offended the gang by attempting to form a new organization called the Texas Syndicate Originales.

•Odilon Hernandez of Lancaster and Jose Lopez of Dallas, who were shot to death March 27, 2003, in a West Dallas home in the 4100 block of Maybeth Street by Syndicate members and associates who conspired to rob the men, thought to be methamphetamine traffickers. A third man, Juan Ayala of Dallas, also died in the shootout, but none of the Syndicate defendants is being held criminally responsible for his death.

•Miguel Elizondo, who was killed in South Texas on May 19, 2003, by members of the Syndicate after weeks of planning.

•Juan Hernandez Jr., 31, who was shot and killed outside the former Club Suavemente on Oct. 3, 2003, by a Syndicate member in training who was under the supervision of his trainer. The men had gotten into a confrontation inside the club and were told to take it outside when the Syndicate members drove up behind Mr. Hernandez, who was riding with a rival gang member, and opened fire. Later, the shooter was considered by the Dallas Texas Syndicate for full membership because of the slaying, the indictment states.

•Mitchell Lozano, 34, of Grand Prairie, who was found dead, shot in the head and neck, on the side of the road in the 2800 block of Spur 408 in the Mountain Creek area Jan. 31, 2004. The indictment states that Syndicate members picked him up and drove him around and shot him when he got out of the vehicle.

•Juan Silva Barrera, who was killed Sept. 25, 2004, in the Dallas area after Syndicate members picked him up and shot him in the front passenger seat. The purpose of the slaying was to maintain the killers' standing in the organization.