By Gary Tuchman and Jessi Joseph, CNN
Los Angeles (CNN) - Former LAPD Detective Federico Sicard still remembers the Monday he arrived at a school to interview children who said a priest had molested them, even though the visit took place 23 years ago.
Sicard found four children at the school, Our Lady of Guadalupe in East L.A., who said they’d been abused by Nicolas Aguilar Rivera, a priest who’d recently arrived from Mexico.
But police never had a chance to interview Aguilar.
“We went to interview the priest and they told us he’s no longer here,” Sicard, who spent more than 20 years on the case, said in a recent interview. “He’s gone. He was taken to Mexico.”
Church officials said they found out about the alleged abuse on a Friday in early 1988 and met with Aguilar the next day to remove him from ministry.
According to a police report, Aguilar told church officials at that meeting that he planned to return to his native Mexico at the beginning of the following week.
The police were notified on Monday morning, but it was too late. Aguilar had already fled the United States for Mexico.
“We made a call to child protective services. Nobody was answering the phone. It was 5 o’clock on a Friday,” said Tod Tamberg, the spokesman for the Los Angeles Archdiocese.
“Monday morning the call was made – a notification was made – and Aguilar Rivera, during the weekend, fled without telling anybody, to Mexico,” Tamberg said.
Sicard said if the police had been notified earlier, Aguilar would have been detained.
After Aguilar fled, more reports of his alleged abuse surfaced. The Los Angeles District Attorney later filed a warrant for his arrest, charging Aguilar with molesting 10 children.
Aguilar is still wanted in Los Angeles for 19 felony counts of lewd acts against a child.
He had been in the U.S. for only nine months.
“We’d love to know where he is, we really would,” Tamberg said. “I mean, the letters demanding his return don’t expire. We’d like him to come back and face justice.”
Aguilar is one of hundreds of former Catholic priests who have faced sex abuse allegations and who now live unmonitored in unsuspecting communities.
For decades, accused priests who were kicked out of the church for allegations of abuse blended back into society. No one keeps track of where they live.
“Unfortunately, they’ve never been convicted,” said Tamberg. “They’re private citizens and so they’re free to move about and live where they want to.”
Nearly 6,000 priests have been accused of molesting children in the United States since the 1950s, according to the U.S. Conference of Catholic Bishops.
Very few of the accused ever make it to a criminal trial, often because by the time the victims come forward the statute of limitations for the crime has passed. At that point, even if a priest admits to the abuse, he cannot go to jail.
CNN has learned that Aguilar allegedly continued his abuse of children after fleeing to Mexico.
In 1992, four years after leaving the U.S., Aguilar surfaced in Mexico City. Still a priest, he was assigned to the church, Nuestra Señora del Perpetuo Socorro, where he met Joaquin Mendez.
“I met him being an altar boy,” said Mendez, 30, who remembered him vividly. He said Aguilar became a close friend of his family.
“Honestly, his presence made me feel uncomfortable. His breath smelled really bad. It was a disgusting smell. Even now I feel the scars of those memories,” said Mendez.
Mendez was 13 years old when, he said, Aguilar called him into his bedroom at the church.
“He said, ‘Come on in. Let me show you some music tapes I made.’ So I go in and then he forced me to pull down my pants. He raped me,” Mendez said.
“I got away from him however I could,” Mendez continued. “He threatened me not to say anything to my family because if I did he was going to do the same thing to my brother.”
But Mendez found the courage to come forward. He said he told his parents and they went to the police.
Aguilar left Mexico City in 1995. Over the next 10 years he continued working as a priest in small towns in the Mexican state of Puebla.
Five formal complaints have been filed against Aguilar in Mexico since his return from Los Angeles. Aguilar is still wanted in Puebla for statutory rape, but authorities there say they’ve lost his trail.
CNN recently received a tip that Aguilar had been seen in Jonacatapec, a small farming town in the Mexican state of Morelos, about two hours south of Mexico City.
Emiliano, a Jonacatapec farmer, told CNN he had seen Aguilar twice. He said he recognized Aguilar from the news. Emiliano took CNN journalists to a bus stop outside of town, the last place he had seen Aguilar.
At the bus stop, a woman told CNN she rides the bus with Aguilar. “I saw him on the bus and he said I should take care of my baby,” she said. “That was all.” She had no idea about his past but agreed to show us where she believed Aguilar lived.
Once in the neighborhood, CNN was unable to find anyone else who knew Aguilar.
Sanjuana Martinez is a Mexican journalist who has written a book about Aguilar. She has also interviewed the priest himself.
“I said I can’t believe it that he’s talking with me,” Martinez said.
In a phone interview with Martinez, Aguilar repeatedly denied the allegations, including the charges made by Mendez.
“All of this has been a series of defamation, slanders,” Aguilar told her. “That is what all of this has been.”
Martinez said she believes it is unlikely Aguilar will ever be arrested in Mexico.
The spokesman for the Archdiocese of Mexico City, Hugo Valdemar, said the church has no further responsibility for Aguilar.
He said the church disputes the claim of rape by Mendez but acknowledged that Aguilar may be guilty of other abuse.
“I’m not saying he may not have done things, because we have the impression that he did,” Valdemar said. “The church has done what needed to be done. It suspended Nicolas Aguilar. He is no longer a priest.”
But church officials in Mexico did not defrock Aguilar until 2009, years after they knew about the alleged abuse. Valdemar said that it’s not the church’s job to hunt down suspects: ”This is a job for the police.”
Tony De Marco is a Los Angeles attorney that represents Joaquin Mendez and others who say they were abused by Aguilar. “There is no desire on the part of the church here to see that he be prosecuted and put in jail,” De Marco said.
De Marco said he would like to see the same policy changes in Mexico regarding victims of clergy sexual abuse that have been made in the U.S.
“You’ve seen things like zero-tolerance policies, you’ve seen compensation to victims, you’ve seen prosecutions of priests and most recently – finally - prosecution of those who facilitated and helped these men ... continue to molest kids,” said De Marco. “Change can happen. That’s my client’s belief and that’s my belief.”
But for now, Aguilar, and hundreds of other accused priests throughout the U.S. appear to remain beyond the reach of the law.
-- CNN’s Luisa Calad, Valeria Longhi and special contributor Jesus Soria contributed to this report.