HOUSTON (AP) _ The last of 14 people indicted for their alleged roles in the nation's deadliest human smuggling attempt is expected to plead guilty next month, according to court documents.

Octavio Torres Ortega, 42, is accused of leading one of the subordinate smuggling rings in an aborted attempt that led to the deaths of 19 illegal immigrants packed in a sweltering tractor-trailer five years ago.

More than 70 immigrants were being transported from South Texas to Houston when the driver abandoned the trailer at a truck stop near Victoria, about 100 miles southwest of Houston.

Torres Ortega, of San Luis Potosi, Mexico, was extradited last year and scheduled to be arraigned April 7, the Houston Chronicle reported.

He was arrested by Mexican authorities in August 2003, three months after the aborted smuggling attempt. But in 2005, charges against him were dropped by a Mexican judge. He was arrested again in 2006 and held until his extradition.

A message left for his attorney Friday by The Associated Press was not returned.

The smuggling attempt began in Harlingen, where dozens of immigrants from Mexico, Honduras, El Salvador and the Dominican Republic were packed inside a tractor-trailer.

During the trip, the immigrants began to succumb to the deadly heat inside. Seventeen were dead at the scene from dehydration, overheating and suffocation. Two more died later.

The truck driver, Tyrone Williams, was sentenced to life in prison. He was the only defendant who faced a possible death sentence.

Others indicted have either been convicted, pleaded guilty or had charges dismissed. Those convicted received sentences ranging from time served to 23 years in prison.

Copyright 2008 The Associated Press.