Abuses by Mexican authorities have persisted even as Mexico has relaxed its rules against illegal immigrants in recent years, according to the National Human Rights Commission.
In 2008, Mexico softened the punishment for illegal immigrants, from a maximum 10 years in prison to a maximum fine of $461. Most detainees are taken to detention centers and put on buses for home.
Mexican law calls for six to 12 years of prison and up to $46,000 in fines for anyone who shelters or transports illegal immigrants. The Supreme Court ruled in 2008 that the law applies only to people who do it for money.
For years, the Mexican government has allowed charity groups to openly operate migrant shelters, where travelers can rest for a few days on their journey north. The government also has a special unit of immigration agents, known as Grupo Beta, who patrol the countryside in orange pickups, helping immigrants who are in trouble.
"In effect, this means that migrants who suffer crimes, including kidnapping, prefer not to report them to avoid … being detained by immigration authorities and returned to their country," the National Human Rights Commission said in a report last year.
As a result, the clause has strengthened gangs who abuse migrants, rights activists say.
"That Article 67 is an obstacle that urgently has to be removed," said Alberto Herrera, executive director of Amnesty International Mexico. "It has worsened this vicious cycle of abuse and impunity, and the same thing could happen (in Arizona)."
A bill passed by the Mexican Senate on Oct. 6 would eliminate the ID requirement in Article 67 and replace it with language saying "No attention in matters of human rights or the provision of justice shall be denied or restricted on any level (of government) to foreigners who require it, regardless of their migration status."
The Mexican House of Representatives approved a similar measure on March 16, but added a clause requiring the government to set aside funds to take care of foreigners during times of disaster. The revised bill has been stuck in the Senate's Population and Development Committee since then.
To discourage migrants from speaking out about abuse, Mexican authorities often tell detainees they will have to stay longer in detention centers if they file a complaint, Vertíz said.
A March 2007 order allows Mexican immigration agents to give "humanitarian visas" to migrants who have suffered crimes in Mexico. But the amnesty is not automatic, and most migrants don't know to ask for it, the commission said.
Hawley is Latin America correspondent for USA TODAY and The Arizona Republic.