Three members of the Texas Syndicate gang who faced trial Monday on federal racketeering charges alleging murder, robbery and drug dealing signed last-minute plea deals.

Pleading guilty Monday were Marco Medina, a former top Texas Syndicate lieutenant in Dallas, and two "soldiers," David Gutierrez, who worked in Dallas and Houston, and Daniel Arredondo, based mainly in Dallas.

U.S. District Judge Ed Kinkeade could sentence Mr. Medina, 35, to up to life in prison.

Mr. Arredondo, 43, faces up to 20 years, and Mr. Gutierrez up to 30 years.

Two co-defendants face sentences of up to 20 and 30 years each; the remaining nine face up to life in prison.

Sentencing hearings are scheduled for August and September.

The case against the Texas Syndicate members was brought under the federal Racketeer Influenced and Corrupt Organizations, or RICO, statute, which was designed to prosecute Mafia members.

This was the first time RICO was used in North Texas to prosecute gang members.

Several of the 14 Texas Syndicate defendants were already convicted in Dallas federal court in a drug distribution conspiracy case and are serving federal prison sentences ranging from 15 years to life.

There is no parole in the federal system.

Some who pleaded guilty were set to testify this week against their former gang associates about up to a dozen Dallas-area murders.

At least one of those who pleaded is in the federal witness protection program, incarcerated at an undisclosed facility, officials said.

Some of his family members are also living under assumed names.

Texas Syndicate members are known for killing witnesses and informants, so as a precaution, nearly a dozen U.S. marshals stood guard inside Judge Kinkeade's 16th-floor courtroom and in the hallways outside for Monday's proceedings.

The Texas Syndicate emerged in the 1970s, when mostly Latino inmates found that they needed protection from rival groups.

It became the most powerful prison gang in Texas, and now has a national presence in state and federal prisons.

The group is secretive, hierarchical and not above slaying other members perceived to be out of line.

Membership is for life, and gang members who are released from prison are expected to do the bidding of those on the inside, mostly involving drug trafficking.