But one cop turned drug dealer turned born-again Christian says he has found the answer to rampant crime and corruption: pray.
Leonel Guillermoprieto, a hulking giant of 37, is the founder of the "Heavenly Police," an organization dedicated to saving Mexico's criminal justice system from its own sleaze via the gospel.
The group's 5,200 members -- retired and active cops and soldiers -- wear uniforms resembling those of the federal police, but with a Bible and cross for a badge.
Instead of "special operations," they run "heavenly ops," visiting police departments across the country to preach and evangelize, on the theory that a God-fearing cop is an honest one.
It is an uphill battle in a country where experts say the police and government are awash in dirty money from the multi-billion-dollar narcotics trade, where more than 185,000 people have been murdered in the past decade, and where more than 90 percent of violent crimes go unpunished.
More than half of Mexicans perceive the police as corrupt, and the country ranks as one of the worst in the world for graft: number 123 out of 176 on watchdog group Transparency International's Corruption Perceptions Index.
Prisoner to preacher
Guillermoprieto says he is uniquely qualified to fight the rot within the Mexican criminal justice system because he himself has seen it from just about every angle.
He started his career as a federal police officer nearly two decades ago.
Then, he says, came the fateful day when a group of drug cartel thugs confronted him with a devilish proposal.
"Do you want these dollars, or do you want us to shoot you full of bullets?" they said, according to Guillermoprieto's own colorful telling of his life story.
"I took the dollars," said the massive ex-cop, who stands 1.94 meters tall (over six foot four) and weighs 160 kilos (353 pounds).
That first fistful of drug money started him down a nefarious path.
He ended up leaving the police force and getting into the narcotics business full time.
"I started going to Central America to buy drugs and send them to Europe. I was making tons of money," he told AFP.
That is, until he was arrested in Guatemala and sent to the United States.
His personal relationship with Jesus Christ began in the unlikely setting of a US federal prison, where he served 15 months for having tipped off traffickers about US anti-drug operations.
There, he started spending time with a group of Christian inmates, who eventually persuaded him to join them by accepting Jesus as his savior.
He still remembers the date: September 22, 2007 -- the same day the "Heavenly Police" was founded, he said.
"We consider the birth of the organization to be the date the founder -- that's me -- dedicated myself to Jesus Christ," he said at a cafe in Tlalnepantla, a Mexico City suburb that is among the 50 most dangerous towns in the country.
Guillermoprieto was facing up to 25 years in a US jail if convicted of drug-trafficking charges, but he ended up walking free.
By his own account, the prosecutor at his trial actually defended rather than accused him.
"God got me out of prison to serve him," he said.
Today, Guillermoprieto tells his story in police departments across Mexico as part of his sermon.
His organization is structured like a police force, with a series of regional commands.
Members do not carry guns, though Guillermoprieto says he has no problem with the real police using them.
"There are people who say, 'Oh, you think you can do it all with the Bible.' But we're not telling (the police) not to use their weapons. We're telling them to use them lawfully," he said.
Some Mexican officials admit the police need all the help they can get.
"We have 250 active duty police officers to cover 265 neighborhoods," said Eduardo Aguilera, the police chief in Tlalnepantla and a member of the Heavenly Police.
"It's impossible to provide full security," he said, before leading a group prayer in his office, where a picture of President Enrique Pena Nieto appears to look at a psalm on the wall.
Mexico is a predominantly Catholic country, though Evangelical Christianity has been growing here in recent years.
Officially, it is a secular state, and Guillermoprieto says the Heavenly Police only preach during the 10 minutes between officers' shifts, without interrupting their work.
He describes his mission as a David-and-Goliath struggle.
"A lot of our colleagues, far from believing in God, are with Satan," he said.
But his faith is unshaken.
"If they kill us doing God's work, we'll die happy," he said.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)