As he set off into the wilderness under a punishing midday sun, Jesse Barajas clutched an orange-handled machete and the dream of finding his little brother, José.

“He’s not alive, no. They don’t leave people alive,” the 62-year-old said as he slalomed through the parched scrubland of tumbleweed and cacti where they had played as kids. “Once they take someone they don’t let you live.”

It has been six months since José Barajas was snatched from his home near the US border, for reasons that remain obscure.

“I think he was working so hard that he forgot his own safety, you know?” Jesse said as he recounted how his 57-year-old brother was dragged from his ranch and joined the ever-swelling ranks of Mexico’s desaparecidos – now estimated to number at least 40,000 people.

Jesse, the eldest of seven siblings, said US-based relatives had implored José to join them north of the border as the cartels tightened their grip on a region notorious for the smuggling of drugs and people.

“We told him how big a monster is organised crime. It is a huge monster that nobody knows where it is hiding,” he said.

Facebook Twitter Pinterest Jesse Barajas searches for the remains of his brother José, who was was dragged from his ranch on 8 April 2019 and has not been seen since, last month near the town of Tecate. Photograph: Emilio Espejel/The Guardian

But José – who had built a successful business making decorative concrete columns for ranches and was in the process of erecting a new house – was adamant he would abandon neither his workers nor his homeland.

“He was a man that believed in Mexico,” said Jesse, who left Mexico as an undocumented migrant aged 14 and is now a US citizen. “He chose to stay here because he thought that he could change things, you know?”

The disappeared are perhaps the dirtiest secret of Mexico’s drug conflict, which has shown no sign of easing since leftist leader Andrés Manuel López Obrador took power last December promising a new era of peace.

Quick guide Mexico's evolving war on drugs Show Hide Calderón sends in the army Mexico’s “war on drugs” began in late 2006 when the president at the time, Felipe Calderón, ordered thousands of troops onto the streets in response to an explosion of horrific violence in his native state of Michoacán. Calderón hoped to smash the drug cartels with his heavily militarized onslaught but the approach was counter-productive and exacted a catastrophic human toll. As Mexico’s military went on the offensive, the body count sky-rocketed to new heights and tens of thousands were forced from their homes, disappeared or killed. Kingpin strategy Simultaneously Calderón also began pursuing the so-called “kingpin strategy” by which authorities sought to decapitate the cartels by targeting their leaders. That policy resulted in some high-profile scalps – notably Arturo Beltrán Leyva who was gunned down by Mexican marines in 2009 – but also did little to bring peace. In fact, many believe such tactics served only to pulverize the world of organized crime, creating even more violence as new, less predictable factions squabbled for their piece of the pie. Under Calderón’s successor, Enrique Peña Nieto, the government’s rhetoric on crime softened as Mexico sought to shed its reputation as the headquarters of some the world’s most murderous mafia groups. But Calderón’s policies largely survived, with authorities targeting prominent cartel leaders such as Sinaloa’s Joaquín “El Chapo” Guzmán. When “El Chapo” was arrested in early 2016, Mexico’s president bragged: “Mission accomplished”. But the violence went on. By the time Peña Nieto left office in 2018, Mexico had suffered another record year of murders, with nearly 36,000 people slain. "Hugs not bullets" The leftwing populist Andrés Manuel López Obrador took power in December, promising a dramatic change in tactics. López Obrador, or Amlo as most call him, vowed to attack the social roots of crime, offering vocational training to more than 2.3 million disadvantaged young people at risk of being ensnared by the cartels.

“It will be virtually impossible to achieve peace without justice and [social] welfare,” Amlo said, promising to slash the murder rate from an average of 89 killings per day with his “hugs not bullets” doctrine. Amlo also pledged to chair daily 6am security meetings and create a 60,000 strong "National Guard". But those measures have yet to pay off, with the new security force used mostly to hunt Central American migrants. Mexico now suffers an average of about 96 murders per day, with nearly 29,000 people killed since Amlo took office.

In August Mexican authorities, who after years of public pressure are beginning to demonstrate greater interest in investigating such crimes, acknowledged over 3,000 clandestine burial sites. More than 500 had been discovered since López Obrador took power.

One as-yet undiscovered grave is thought to guard the remains of José Barajas. And one recent morning his family set off to find it, in the company of a government forensic team and – a heavily armed federal police escort.

“It just sucks not knowing where he’s at,” said the missing man’s 28-year-old son, who is also called José and had travelled from California to join the search.

Facebook Twitter Pinterest Forensic experts work with police protection during a search for the body of José Barajas last month. Photograph: Emilio Espejel/The Guardian

The mission – one of the first conducted in conjunction with a newly created state search commission – began shortly before noon as searchers formed a human chain to comb a stony heath east of José’s ranch.

Jesse struck out ahead, pausing occasionally to skewer the ground with his machete. After puncturing the earth, he would raise the blade’s tip to his nose in the hope of detecting the sickly scent that might reveal the whereabouts of his brother’s corpse. Other searchers probed soft patches of soil with T-shaped steel rods.

Minutes later, Jesse spotted a black bomber jacket, half buried in the soil. He quickly decided it was not his brother’s but photographed the garment with his smartphone: “Maybe somebody is looking for somebody with this jacket, huh?”

As Jesse marched on – shadowed by a rifle-toting police agent – the hidden perils that lay behind his brother’s disappearance became clear.

Pickup trucks, apparently sent by cartel bosses to monitor the search party, rattled past on the country lane down which José’s abductors fled.

“These assholes are halcones,” Jesse complained, using the Spanish slang word for lookouts.

Unsettled by their presence, Jesse radioed another nearby search team to request a protective roadblock.

“They’re spying on us … watching our movements to see what we are looking for and what we are doing,” the police officer said.

Nerves jangled as the hawks continued to circle. “The criminals here are very bloody. They are beyond limits,” Jesse murmured as the police agent trained his gun on the road.

Twenty tense minutes later, reinforcements arrived. But the drama was not yet over. As Jesse clambered into the open back of a police vehicle two shiny SUVs appeared on the horizon and sped down the sun-cracked asphalt towards the group, before being forced to stop.

Facebook Twitter Pinterest A relative shows a photograph of José Victoriano Barajas, 57, a businessman who is feared dead. Photograph: Emilio Espejel/The Guardian

As the police car’s occupants braced for a gunfight, two men descended from the first SUV and exchanged a few inaudible words with the federal agents before the second car was allowed to pass unmolested.

The identity of its occupants remained a mystery. But as the vehicle raced away it left the unshakable impression that a local crime boss had been inside – and a serious confrontation narrowly avoided.

“We’re in a hostile place – and it’s not Iraq,” Jesse said as the team regrouped, heaving a collective sigh of relief.

After a lunch of energy drinks and granola bars, the hunt for José resumed.

“All we want to do is give him a proper burial, like every human,” the missing man’s son as a sniffer dog joined the search.

José’s son said relatives had not told his 92-year-old grandmother, who suffers from Alzheimer’s, what had happened and had yet to fully comprehend it themselves. “I guess we have to be OK with not being OK,” he said.

Once his father was found, José said the family would sell up and cut ties with the land his father had so loved. “It’s not the same any more, you know what I mean?”

Three hours later, nothing had been found but coyote bones and clothes ditched by migrants as they trekked towards the US. Back at his brother’s ranch, Jesse busied himself handing out burritos and spicy nachos to the famished searchers.

Fernando Ocegueda, the activist who had organized the mission, insisted searchers should keep faith. “Once we spent 15 days searching and found nothing – and on the last day we found three bodies.”

Facebook Twitter Pinterest Jesse and Alfredo Barajas, two of the victim’s brothers, and his son, José, searched an area near his ranch last month. Photograph: Emilio Espejel/The Guardian

“This kind of activism is about patience, not speed,” Ocegueda later added.

Two days later, after a second fruitless hunt near the ranch, the Barajas family headed south to join another search, though this time not for José.

Outside a police station in the coastal town of Ensenada they met dozens of mostly female searchers – members of a local “collective”hoping to find their loved ones.

As the group explored its first location – a rocky wasteland behind the town’s country club – terrible stories of violence, fear and grief emerged.

“It was my nephew. They took him 18 days ago,” said one thirtysomething woman, who – like all of the collective’s members – asked not to be identified for fear of the cartels.

“My brother,” said a 15-year-old boy as he pummeled the earth with a shovel. “Three weeks.”

Another woman said she was seeking her son. “In December it will be six years since they disappeared him … and I’ve been in this fight ever since,” she said.

As the minutes and hours ticked by and no bodies were found, bloodshot eyes shed tears of sorrow and there were crossed words of frustration.

“It’s like looking for a needle in a haystack,” José’s son complained after a traipse through the wasteland found only swarms of bees and a poisonous snake.

But as the group moved from the viper-infested wild to a reeking landfill and, finally, a junkyard police suspected had served as a torture centre and burial ground, there was also camaraderie and warmth.

The bleakness of the task was tempered by shared experiences and laughter. Jokes were told. New friendships formed.

“We all have the same goal, which is finding our missing ones,” said Ocegueda who became a campaigner after his own son was taken, in 2007, and has recovered more than 120 bodies since.

Ocegueda has yet to locate his son – but he has found a calling. “This is where I like to be because it’s here I’ve found my people,” the 62-year-old said. “Along the way you make friends – and this is the most important thing.”

Facebook Twitter Pinterest A police vehicle parked outside the unfinished home that José Barajas had been building when he was abducted in April for reasons that remain a mystery. Photograph: Emilio Espejel/The Guardian

Also present was a woman still grappling with a more recent loss: José’s 49-year-old wife, Irma Bonilla Barajas.

Visibly drained, Irma threw herself into the search operation, determined to bring others closure, even if she had yet to find it herself.

Pausing from her digging, Irma remembered a hardworking family man whose absence was still sinking in. “He was so, so intelligent,” she said. “He used to calculate all the exact measurements for the concrete and his gazebos in his head.”

Six months after José vanished, Irma voiced bewilderment at the “evil minds” responsible for snatching so many Mexican lives.

“I just can’t make sense of it … If they’ve already killed them, why don’t they leave them for us?” she wondered. “What more harm can they do to them, if they are already dead?”

Additional reporting by Jordi Lebrija