The leader of a Texas prison gang is facing at least 10 years in prison, as well as a fine of up to $10 million dollars.
Eric Gomez, of San Antonio, pleaded guilty to distribution of heroin in a federal court Wednesday in Houston.
A federal judge said Gomez should be sentenced later this year.
Prosecutors describe Gomez as a general in the Texas Mexican Mafia prison gang.
Investigators said Gomez was behind the sale of more than 12 pounds of heroin to an FBI confidential source since late 2011.
Gomez was among more than two dozen alleged gang members charged last fall with running drugs and gun violations to support the group's violent activity.
About half of the defendants have pleaded guilty.