Mexico City ? Six U.S. law enforcement officials, including a federal prosecutor, are targets of a lawsuit alleging they were negligent in not preventing the killing of Luis Padilla Cardona, an American citizen whose body was found in Ciudad Juarez, Mexico.

Padilla’s body was one of 12 unearthed last January in the back yard of a home in a Juarez neighborhood.

The lawsuit, filed by Dallas attorney Raul Loya on behalf of the Padilla family of Socorro, Texas, asserts Immigration and Customs Enforcement officials Michael Garcia, Giovanni Gaudioso, Patricia Kramer, Curtis Compton and Raul Bencomo, along with Assistant U.S. Atty. Juanita Fielden, approved the activities of a U.S.-paid informant who participated in the killings of Padilla and others.

The informant, known as Lalo, was employed by ICE. The lawsuit charges the officials could have prevented the death of Padilla, then 29, by alerting him or his family about Lalo’s activities.

“All killings after August 2003 could have been prevented,” the lawsuit states. “At the very least, the … operation should have been shut down.”

It added, “Padilla was killed due to the negligence and conscience (sic) indifference of the Bureau of Immigration and Customs Enforcement and the assistant U.S. Attorney in El Paso.”

The lawsuit, filed Thursday in federal court in El Paso, Texas, and announced Friday, seeks unspecified damages and attorneys’ fees.

An ICE spokeswoman in El Paso, citing an internal ICE investigation, declined comment. Calls placed to the U.S. Attorney’s Office Friday were not returned.

ICE documents obtained by The Dallas Morning News indicate Lalo assigned corrupt policemen their roles in several killings, called in gravediggers to bury bodies and paid off killers.

“In the course of six months, (the informant) participated in the killings of over 12 people, possibly more,” the lawsuit states. “In each incident the informant was instrumental in luring the victims to the house on Parsioneros Street in Juarez, Mexico, where the killings occurred.”

The first of the killings referred to by the lawsuit was that of Durango lawyer and suspected drug trafficker Fernando Reyes Aguado.

In Washington, a U.S. official, speaking on condition of anonymity, said the Mexican government was preparing to seek the extradition of Lalo, who remains under U.S. federal protection in an unknown location.

The attorney general’s and foreign relations offices in Mexico City declined comment on the extradition question Friday.