I found this article with some contact numbers for inquiring in Mexico...
The article is not relevant, but I include it for the contact and as an indication that there are lots of unidentified persons in mexico, but getting the info is somewhat problematic, sigh
http://www.highbeam.com/doc/1G1-57882755.html
Digging starts for 120 remains in Mexico: 600 soldiers plus FBI unit of 100 seek drug lords' victims, some American.(Nation)
From: The Washington Times | Date: December 1, 1999 | Author: Aynesworth, Hugh | More results for: mexico unidentified persons
CIUDAD JUAREZ, Mexico - The first human remains were found yesterday in the search for more than 100 victims of Mexican drug lords.
A large contingent of FBI agents and hundreds of Mexican soldiers and police continue searching for bodies around two remote ranches about 10 miles south of here.
"At this stage there are four sites where there could be human remains . . . and we are carrying out thorough investigations at two," said Jose Larrieta Carrasco, head of the organized crime unit of the Mexican Attorney General's Office.
Assistant FBI Director Thomas Pickard said in Washington that agents found part of one body yesterday morning. An El Paso, Texas, source, a local lawman, said two more were found later in the day.
"We believe these people were killed for their knowledge or for being witnesses to drug trafficking endeavors," Mr. Pickard said. "Most of the information we have shows these individuals were buried there at least two or three years ago, so it's not a recent situation."
"We have at least a hundred people there [investigating]," said Mr. Pickard, "the Mexicans have six or seven hundred."
Mexican Attorney General Jorge Madrazo said 120 persons could be buried in the ravines and trenches. Several sources said 20 to 25 Americans could be among the victims.
"The list is more than 100 persons who hypothetically could be buried in those points," Mr. Madrazo told the Televisa network yesterday in Mexico. Later he specifically mentioned a list of 120 missing persons they were seeking, 22 of whom are Americans.
At an El Paso news conference yesterday, officials said they were not looking for the bodies of any agents of the U.S. Drug Enforcement Administration or the FBI.
Mr. Madrazo said the victims died at the hands of the Juarez drug cartel, one of the most vicious trafficking organizations the past five years or more. Most were believed to have been either informers or people closely aligned with rival organizations.
Agents at the scene yesterday weren't talking, but some local officials close to the investigation - now several weeks old - said the Mexican government was informed of the burial site by an unidentified Mexican police officer accused of several murders. Other media reported that the ex-officer had passed a polygraph test.
On Monday night, dozens of Mexican soldiers, guns drawn and black ski masks hiding their faces, surrounded one of two targeted ranches - some scaling a concrete wall topped with razor wire to gain entrance.
The ranch is located on a two-lane highway with little more than desert close by. A junkyard sits across the highway. The area is not lighted.
Rodrigo Falcon, 18, told reporters Monday night his family had been taking care of the Ortiz property for about two years. When he returned from his job in Juarez, he said, Mexican soldiers refused to let him enter the property. He said his family was detained inside.
At Mexico's request, the United States has ordered 68 FBI agents and forensic experts, plus support personnel, to help examine the ranches. Part of the U.S. contingent had recently returned from a investigation of possible war crimes in Kosovo.
"It's a major enforcement initiative by the U.S. and Mexico," said Louis J. Freeh, FBI director.
While the expected body count is vast, several times that many people have been reported missing in the past four or five years in Mexico, a direct result of the continual battle for control of the billions of dollars realized from narcotics trafficking across the U.S.-Mexican border.
Mexico's Attorney General's Office gave two phone numbers for people to call to pass along information or to inquire about missing family members: 800/338-5856 and 800/716-7852.
A Texas missing persons association said it was flooded with phone calls yesterday from hundreds of relatives of people who disappeared from Ciudad Juarez.