A stone's throw from the neon lights of Tijuana's bars and clubs, Andres Herrera was down a dingy alley injecting himself with heroin and crystal meth – bought with money stolen at gunpoint from a tourist that day.
'I have to get a fix every five hours or I'm likely to do something even worse,' his native California accent trembled as he fumbled his forearm to find an unscarred vein.
'I'm planning to cross back illegally into the US soon. Even if they catch me, prison over there is a lot better than life here in the Zona Norte.'
Andres is one of 20,000 Mexican-criminals, who were taken across the border to America as babies where they grew up.
But despite speaking no Spanish and having never lived there, once they served time in jail, America washed its hands of them - and sent them back to Mexico.
Most of the men like Andres end up on drugs living in the crime-ridden district of Zona Norte in Tijuana - directly beside the triple fence that separates their adopted home of the United States from Mexico.
Ninety percent of the Zona Norte deportees are drug addicts, and all are waiting for their opportunity to sneak back over the border and go 'home'.
Just over half of the total narcotics that are smuggled into the US go through the Tijuana border region.
The brutal Sinaloa Cartel that controls criminal activity throughout north-west Mexico has turned the once-peaceful 'North District' into a drug-ridden hell hole.
'It was very peaceful here when I was a child,' local businessman Roberto Martinez told MailOnline.
Roberto owns a tailoring business beside the alley where Andres was injecting 'speedy' – the name given to the mix of heroin and methamphetamine that is preferred by many drug users in Tijuana.
'Now it's all gangs, violence, drugs and poverty,' he lamented. 'I stay out of it. What happens on the other side of my shop door I'm not interested in.'
The dilapidation of the Zona Norte is extreme. Local landmarks consist of graffiti-covered houses and burned-out cars.
Drug-addicts rummage through waste bins for food and plastic bottles to sell to recycling centres.
Drug paraphernalia is everywhere: syringes strewn on the pavements, spoons used to prepare intravenous drugs sit on windowsills, street market stalls sell Snickers bars alongside crack-pipes.
Cartel lookouts are present on every corner, masked gangsters openly carry pistols in their waistbands and drug dealers hiss from behind barred windows, flashing tinfoil-wrapped packets of heroin for five dollars apiece.
'Around 60 per cent of the people who live here are drug addicts,' a local police officer told MailOnline. 'If we're talking in terms of the deportees, nine out of ten are junkies.'
1,700 people regularly attend the local council's weekly needle exchange, which sets up its stall along the neighbourhood's main street. 70 per cent of the people who trade in their syringes have hepatitis C. Many others carry syphilis and HIV.
Over the past five years, over 600,000 people have been deported to the Mexican state of Baja California, where Tijuana is the largest city.
36 per cent of these deportees remain in the Mexican borderlands, the majority of which have spent most of their lives in the United States.
Known to the locals as 'chicanos', a pejorative term for Mexican-Americans, they are rejected by Tijuana society, and without Mexican paperwork that will allow them legal employment, many turn to drugs and eventually to crime.
'I couldn't get a decent job here because of my tattoos, so I turned to the easy money in crime,' said Mario Villarino, who worked for the Sinaloa Cartel in Tijuana for eight years after being deported for armed robbery.
Mario says he made many contacts during his three year stretch in federal prison and already had a job waiting for him in Tijuana when he was finally deported.
Starting as a debt collector, he worked his way up the gang hierarchy until he was running the local kidnapping racket.
'I did terrible things, and nothing ever happened to me because the cartel controls things here,' he said.
When he finally entered a rehabilitation centre to deal with his drug use, he became a Christian missionary and remained in Zona Norte helping the constant stream of fresh deportees.
'I don't want to be here, but I hurt so many people with kidnappings and violence that I have to try and make things right.'
'It's very easy to slip into the criminal life here because we're outsiders,' he said, speaking at La Roca refuge where he now receives the recently deported.
'You get desperate and turn to crime. The deportees define this neighbourhood now, but they've also changed it completely.'
'The largest problem they face is that, as we say, "they're not from here, nor from there",' local government deportee program director Rosario Lozada told MailOnline.
'These people end up very resentful of society, and that can create an individual who is a danger to society.'
'They start to take drugs to forget, but they end up taking drugs just to survive and doing whatever they can to get ahold of them.'
The district is filled with drug dens masquerading as deportee refuges. These establishments charge a dollar per night for a dirty mattress behind a closed door and no further questions. It's these places where many of the deportees stay when they arrive.
The Zona Norte borders on Coahuila, a touristi district of Tijuana filled with bars that welcomes thousands of visitors from the United States every weekend.
Local police warn against straying too far from the bright lights, but those tourists who find themselves on the wrong side of the tracks often become easy prey for the gangsters.
Many of the deportees in the Zona Norte, despite hailing from different parts of Mexico, say they stay in Tijuana waiting for their chance to illegally cross back into the United States
'My father's in Guadalajara, but I've never even been to visit him,' says Moses Vasquez, 36, who was taken to Pasadena when he was just a month old and was deported last year.
'Mexico has nothing for me and the further I go from the border, the more I feel that I'll never go back'.
'You've got to wait for a few days of cloudy weather,' he told MailOnline at the soup kitchen where he works, 'that's when you've got your best chance as the border patrol's instruments don't work as well'.
'I like Mexico, but I'm an American,' he says. 'The hardest thing about being deported is being separated from your family.
'The justice system has to take the human consequences of deportation into account. It has caused suffering on both sides of the border.
'Immigration law is definitely ripe for review,' US deportation defence attorney Edward Haase told MailOnline in his offices in San Diego, California. 'Both sides have a compelling argument.
'If it just affected that one person I could almost condone it. However, it affects the entire family when you take the main breadwinner away. People end up suffering on both sides of the border.
'The justice system argues that when people want to enter the United States there is a procedure that should be followed: you apply for a visa, you wait your turn.
'So these folks that bring over their children are now being able to jump the line and it puts everyone else at a disadvantage.
'I hate Tijuana', says Juan Alvarez, who was deported three years ago and finds it difficult to find work as a result of his LA gang tattoos. 'The only reason I stayed here is to be close to my family in Los Angeles.'
'The advice we give to the recently deported is to leave as soon as possible. To try and get in touch with the family they still have in Mexico and start building their lives over again', says Rosario Lozada.
'Tijuana ends up destroying nearly every outsider who stays here.'