Negrete has even visited morgues and cradled dead babies, including one she said was mutilated, searching softly with her fingers for the distinctive mark that separates her child from others.

But she has never found that special spot on her baby's chest, and DNA tests taken from her and the small bodies have confirmed her doubts.

Jonathan Ivan Esquivel Negrete will be 5 years old May 26, assuming he is alive. But the young mother with dark, sad eyes and long black hair has not given up her search. Fighting tears, her chin quivering and mouth puckering, Negrete whispers that it would be better to find out her baby, her first-born, was dead.

Much better, she said, than the interminable anguish, the sleepless nights of blaming herself, of not knowing where he is, who has him or why he was taken. Of not knowing if he is alive.

"I pray to God he will help me find out what happened. In the best of circumstances, a good family has him, but I just don't know,"said Negrete, 27. "I didn't stop crying until I got pregnant again. The doctor said it was bad for my pregnancy. Before that, I wanted to kill myself."

She is one of hundreds of mothers in Mexico who claim their children were stolen or kidnapped from homes, schools, streets, parks or malls, never to be seen again. They suspect their children were sold for illegal adoptions, prostitution, child pornography, forced labor and even for the trafficking of organs.

At a time when the U.S. Congress has called for better cooperationin tracking American children abducted during custody fights to other countries, including Mexico, the issue of missing Mexican children gets barely a mention.

It is the other side of a story cloaked in silence and malevolence.

In Mexico, families with missing children have no answers. They are lonely voices screaming for justice, for a resolution and government recognition of what they claim is practically anepidemic of crime rings trafficking in children.

In a country where political and drug crimes get all the publicity,where children are coddled and spoiled, it is Mexico's dark secret: Babies, infants and teen-agers are disappearing. Some accounts put the rate at one per day; others say it's much higher.

Not much is being done about it, although the governing Institutional Revolutionary Party in the Senate recently proposed legislation to increase jail time to a minimum of 60 years for a kidnapper of a child under 12 years of age.

It also called for the creation of a special agency overseen by the federal attorney general to investigate crimes against children.

Still, Mexico lags behind the rest of the world in legislation to combat the problem.

There is no national data bank on the names and numbers of disappeared children and no single government agency dedicated to finding them.

The federal attorney general's office oversees such cases, and since 1990 Mexico City's attorney general has operated the Center of Support for Missing Persons, but it doesn't investigate.

Mexico is among 28 countries that signed The Hague Convention on Protection of Children and Cooperation in Respect of Inter Country Adoption. Under the agreement, it is required to name authoritiesresponsible for controlling the trafficking of children.

Discussion has been under way to create such a special agency, butit has yet to develop. Officials from the Foreign Relations Secretariat, the president's office and the attorney general have been in contact with the National Center for Missing & Exploited Children in Alexandria, Va., to join forces. But it has yet to come to fruition.

Repeated requests over more than a month for interviews with federal attorney general officials, the foreign relations ministry and other authorities were not answered.

A hidden crime

Because there are no official figures, there is no way to know how many children run away, how many are taken in divorce or separation disputes, how many are kidnapped for ransom, how many are used in illegal adoptions or how many are used for prostitution or child pornography.

A special report published in 1998 by the United Nations Human Rights Commission chastised Mexican officials for a "hermetic and defensive attitude still in a denial stage."

The report also lambasted Mexico's child legislation for not being up to "pertinent international standards."

"The most common and visible sexual commercial exploitation of minors in Mexico is prostitution," the report said. "Children who live in border states are more susceptible because these zones are preferred in the production of child pornography for easy transport to the United States."

It is a hidden crime known only to the affected: the mothers,friends and relatives of a missing child.

"When people rob a bank, there are cameras. But if you steal achild in circumstances no one sees, we are talking about an invisible enemy," said Guillermo Gutierrez, who runs one of th elargest private organizations in Mexico dedicated to finding missing children.

"There is not a trace of anything," said Gutierrez, who heads the National Foundation of Investigations of Stolen and Disappeared Children and has been trying to establish links with the Center for Missing & Exploited Children in Virginia. "In the United States, you have help from the government, from the FBI, from private corporations. In Mexico we are on our own."

It is one of dozens of such private groups throughout Mexico. Their names alone capture the plight of Mexican families with missing children: Looking for Our Children Foundation, Foundation of LostChildren of America, Association Searching for Our Children, Association for the Recovery of Lost Children of Mexico, Foundationfor National Investigations of Stolen Children, Foundation of Stolen Children of America.

In interviews in Mexico City with five organizations, each claimed to be working on an average of between 80 and 100 unresolved disappearances of children, many of them the same cases.

Most of the organizations were established in the early 1990s, when they say such incidents began to rise.

The only organization with a breakdown of the percentage of cases is the Association for the Recovery of Lost Children, run by accountant Israel Betanzos.

He said about 60 percent of the cases he handles are custodial. That is, a husband or wife took the child. But he said between 30 percent and 40 percent are stolen or kidnapped. Other organizations agree on the breakdown.

"Police don't help us. When we call them, they want money," said Betanzos, who wants to establish an alliance with the Heidi SearchCenter for Missing Children of San Antonio. "But all the victims are poor. They barely have enough to eat."

The way Betanzos' and other organizations work is through footwork and with the help of volunteers. From tips, they go where they believe a child might be held. Scrounging bus fare, they scour the nation and often cross the border.

"We watch for days, quietly without being seen. Once we confirm it is the child we are looking for, we go to the police," Betanzos said. "Only then will authorities make an arrest."

With little support from government or police, these small organizations have become their own detective agencies, spending their own money to pay bus fare, make telephone calls and print fliers. They stage protests and give interviews. They hope and pray. Sometimes, in their obsession, marriages fall apart.

They have unsophisticated networks of sources throughout Mexico to help them follow leads from anonymous callers who report seeing a child who looks like a photo on a flier.

Once in a while they get lucky.

Betanzos said if a child is under 3 years of age, the chance of recovery is virtually nil.

"Minors who are stolen are becoming younger all the time. That way they can't remember their parents or talk about their families, and in many cases they don't even know their name," the newly created Federal Preventive Police said in a statement in March.

"They are stolen for sale to illegal adoption networks that take them out of their country, and are exploited in various forms, including sexually, for pornography and prostitution," it said.

On March 9, after a three-month investigation, the Federal Preventive Police arrested sisters Elizabeth and Beatriz Rodrguez of Austin on charges of trying to cross the border with an 18-month-old Mexican baby girl.

Police allege the sisters are part of a ring that operates from Chiapas, Chihuahua, Coahuila and Oaxaca, trafficking in undocumented workers and minors to sell in the United States.

In a videotaped interview with police, the women said they were paid $1,000 to deliver the child to family in Austin. One said she transported two other 2-month-old babies across the border this year. But the women denied trafficking in children for illegal adoptions or other illegal purposes, saying they were only reuniting infants with parents who had crossed the border in search of work.

Afterward, the sisters denied everything.

"Trafficking in children is less risky and more lucrative than trafficking in drugs. There is no overhead, no laboratories to worry about, no middlemen," said Claudia Martinez, a spokeswoman for the Federal Preventive Police. "The trafficking of people, of undocumented workers, of prostitutes, of children, of organs, is all related and well-organized."

She trusted them

Negrete's son was so young, the family had yet to take his photo. All she has is a crude drawing printed on fliers.

It was 8:30 a.m. on July 5, 1995. The city was Nauclpan, in the state of Mexico, a mostly rural state on the outskirts of Mexico City. Her son had been born a month earlier.

Negrete was rushing to get the baby ready to go out and get his birth certificate at the national registry. He was ready to go, diaper bag nearby.

She said there were two women. One claimed to be a social worker,and the other was clad in a nurse's uniform, a stethoscope around her neck.

Negrete was not suspicious because she met one of them two days earlier outside the hospital where she had taken Ivan to be examined.

"They stopped me on the street and said they were taking a census.I gave them my address, my name and Ivan's name, and that was it," she said. "I didn't see them again until they came to my door two days later.

"They said they wanted to corroborate my address and to find out if I lived alone and if it was my first baby," Negrete said. "They wanted to know if the baby was healthy. They made small talk. I told them I had to go out and to wait while I went to the bathroom to get dressed."

Less than five minutes later, when Negrete stepped out of the bathroom in her street clothes, the women were gone. So was her baby.

"I started screaming 'My baby was stolen!' I ran to the street like a madwoman, yelling 'My baby was stolen!'" she said, sobbing at the recollection.

Police came. Negrete gave a description of the women. One of them, the one dressed as a nurse, was caught. She is serving a 27-year sentence for accessory to a crime. But she has never discussed the case, not to authorities, not to Negrete.

"I begged her to please tell me where my baby was," Negrete said. "But all she ever said was that she didn't know."

The case attracted so much publicity that Negrete began getting anonymous telephone calls with people claiming they knew where Ivan was.

"I've traveled all over the country. I've been to Guatemala, to Miami. I answer all the calls because you never know," she said. "Sometimes I get calls and there is a baby crying at the other end. I want to die when that happens. There are mean people in this world."

Today, Negrete ties her new daughter to her wrist when they go out.

"People look at me as if I'm crazy," she said. "But they are the crazy ones if they think their child is safe. I don't care what they think."

Bring in the clowns

The children's organizations say kidnappers use all means to take a child when parents have their guard down.

"The kidnapping of newborn babies from hospitals and clinics by people dressed as nurses is very common," said Gutierrez, a business administrator who founded his organization after running the Mexico City attorney general's Center for Missing Persons.

"There is also what we call 'shopping from a catalog,' which happens in poor, rural areas," he said.

A few years ago, Gutierrez said, officials discovered a clown ring that traveled to remote indigenous villages in the states of Guerrero, Oaxaca and Veracruz to entertain children and take their photographs.

"The whole village came out, children, parents to see the clowns. They gave out candy and told jokes," Gutierrez said. "When the games were over they took photographs of the children."

A couple of months later, the clowns return to the villages bearing gifts for the children.

"They give presents except to certain ones, the ones selected in photographs," Gutierrez said. "To those they say 'Oh, no! We've run out of toys, but there are more in our van if you come with us.'"

The children follow and are locked inside, not to be seen again, Gutierrez said.

"These rings operate where there is poverty, where people have no power or political clout," Gutierrez said.

Children's organizations say a child can bring anywhere from $10,000 to $100,000 depending on skin and eye color. The whiter the skin, the more expensive.

A 'lucky' one

In a working class neighborhood of Mexico City, 6-year-old Carolina Peralta was just home from school when a man knocked at her home asking for directions to the nearest pharmacy.

Hesitant, Carolina said she would ask her grandmother, but the man persisted and Carolina walked one block with the stranger to show him the drugstore. She never arrived. The man put chloroform over her mouth and placed the unconscious child in a car.

It was Oct. 8, 1990.

Carolina's story is also the story of a grandmother with long gray hair held neatly in a braid, a grandmother who conquered shyness and became an expert at dealing with bureaucracy and speaking with the media.

It is the story of never giving up.

"For three years ... I came to know all the northern border cities.I went to New Mexico, Dallas, San Antonio, El Paso," said Armentade Loz, 57. "I went to schools, I met the sheriffs, I was interviewed on radio and TV.

"Sometimes I didn't have enough for food, just for bus fare, but I didn't care if I ate as long as I could pass out fliers with Carolina's picture," she said. "I never rested one day without looking. I never lost faith."

It paid off. On Oct. 26, 1993, de Loz and her daughter found Carolina. They had gotten a tip about an abused girl who slept on the floor in a market in the city of Puebla, in the state of the same name, the virtual slave of a merchant.

"I saw her and I nearly fainted. I couldn't help myself, "I cried: Carolina!" she said.

"She was afraid, she was dirty, skinny and her hair was dyed blond," de Loz said.

The man who took her recently died in jail, and Carolina, now 15, is undergoing psychological therapy and trying to be a normal high-schooler.

"He told her he would kill the rest of her family if she told she was stolen. He changed her name to Eloisa," said the grandmother, who runs the small Foundation of Lost Children of America out ofher modest home.

Monica Corona, 34, is still searching for her daughter.

Corona said in 1995 her 10-year-old daughter, Yasmn Monserrat Herrera Corona, and her best friend Ana Lilia went to buy bread a block from their home. They never came back. A witness said he saw a couple driving a car with tinted windows and no license plates snatch them off the street.

For three months after the kidnapping, Corona cried nonstop. She even tried to kill herself by jumping in front of a subway train. Her husband pulled her to safety.

"'I'm crazy,' I thought," said Corona, who then decided to shed no more tears. She went to work with the Looking for Our Children Association, which she now directs.

Corona is convinced her daughter and friend were taken to the netherworld of child prostitution. She has visited brothels all over Mexico and Central America, showing a color photograph of ashy-looking Yasmn in her school uniform.

Working as a maid and making trinkets to sell at markets, Corona made enough money to take a computer course and a course in management. She is organized and all business, in the business offinding children.

"I have other families counting on me. If I fail and they see mecry, they have no hope," Corona said.

"Many parents get tired and give up. They are afraid of authorities. Police say they will investigate if you give them money for gas. There are no records, no investigations and no follow-ups. Families leave their office in tears. These are the uncounted ones."

When Corona walks into a government office with a big file of children's photographs under her arm, receptionists squirm. Everybody knows her.

"How is it possible that theft of a car is a federal offense but stealing a child is not really theft?" said Corona, who is also lobbying to change legislation.

In the meantime, Corona still combs the Mexico City streets where young prostitutes prowl, passing out her daughter's photo.

"I hope she knows I'm out here looking for her, that I haven't given up," said Corona, who is planning to travel to Tijuana, where she heard a teen-ager resembling her daughter was working at a border brothel.

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