FARGO - The lawyer for the alleged ringleader in a drug conspiracy case says his client decided to plead guilty after poring over 30,000 pages of evidence.

Jorge "Sneaky" Arandas softly entered guilty pleas Thursday to 13 federal counts, including murder in furtherance of a continuing criminal enterprise. Authorities said Arandas ordered the killing of Lee Avila, 28, of East Grand Forks, Minn.

Defense attorney Steven Mottinger, who two months ago said his client had no incentive to deal, agreed that it's unlikely Arandas will be spared a life sentence.

"He came to the conclusion that this was the best way to end this," Mottinger said outside the courthouse.

Arandas was "a gentleman to work with" and "took responsibility for his actions," Mottinger said.

U.S. Attorney Drew Wrigley said he gives Arandas credit for realizing the evidence was overwhelming against him.

"Some people just want a clear conscience, too, believe it or not," Wrigley said.

Arandas faces a maximum penalty of 10 life sentences and a $50 million fine. Sentencing is set for Feb. 8.

Prosecutors said Arandas, 26, led an operation that brought drugs from Mexico and the West Coast to North Dakota, Minnesota and other states. The indictment said he intended to deliver more than 500 grams of methamphetamine, more than 500 grams of cocaine, and marijuana. He also was charged with money laundering.

Prosecutors said Arandas hired people to transport and distribute drugs, as well as transport drug money to deposit among banks in several states. Most of the money went to banks in the Yakima, Wash., area, prosecutors said.

Assistant U.S. Attorney Chris Myers said during the hearing that Avila was killed in a dispute over what Arandas said was a 5-pound shipment of methamphetamine. Avila had claimed the delivery was smaller, Myers said.

"That shipment ultimately resulted in the death of Lee Avila," Myers said.

Myers said Arandas sent Gabriel Martinez, Alan Wessels, Michael Petzold and Martin Carrillo to East Grand Forks to "either collect the money or take care of the issue." Martinez shot Avila to death, Myers said. All five men were charged in the killing.

Petzold pleaded guilty to his role in Avila's death and agreed to cooperate with prosecutors. He was sentenced to 30 years in prison. Earlier this year, government prosecutors decided not to seek possible death penalty sentences against the four other defendants.

Wrigley said 46 of the 51 defendants have been convicted in the case known as "Operation Speed Racer." Four other defendants, including Gabriel Martinez and Wessels, are scheduled for trial on Jan. 22. Carrillo remains at large.

"The noose of Operation Speed Racer is continuing to tighten around this group," Wrigley said.