The MS-13 gang leader sometimes known as “the Tapeworm” had already been deported from America at least three times and escaped from a Honduran prison when authorities were hunting for him in 2004, suspecting he had masterminded an attack on a bus full of Christmas shoppers.

After rounding up some suspected gang members and demanding to know who they were and where they came from, a top Honduran security official recounted, one of the suspects offered a response that encapsulates the challenges in fighting a criminal enterprise as indifferent to borders as it is to violence:

“Esta pandilla no tiene bandera,” the suspect said. “This gang has no flag.”

In the decade since, MS-13 has only grown in strength, consolidating its control over a broad swathe of Central America – and to the current president of the United States, the group consists of “violent animals”. It is a refrain Donald Trump has repeatedly espoused, amid more than a dozen tweets about the gang, invoking MS-13 to demonstrate the perils of lax immigration enforcement and vowing to dismantle the group through a programme of mass deportation.

“We’re taking them out by the thousands”, Mr Trump boasted during a visit to a border wall prototypes in California. Although the US government does not track MS-13 deportations specifically, it claims some 5,400 gang members were removed in 2017.

But current and former law enforcement officials who have contended with the gang’s rise say a focus on deportation belies the complexity of the fight – and risks fuelling the cycle that nourished MS-13’s rise in the first place.

“Deportation doesn’t do a thing for MS-13 because it’s so easy to get back in. They’re very well entrenched”, said Chris Swecker, who oversaw the establishment of FBI gang task forces. “Instead of putting them in jail we deported them, which they laughed at – ‘send us on vacation, we’ll visit the homies and come back in’.”

World news in pictures Show all 50 1 /50 World news in pictures World news in pictures 14 September 2020 Japan's Prime Minister Shinzo Abe, Chief Cabinet Secretary Yoshihide Suga, former Defense Minister Shigeru Ishiba and former Foreign Minister Fumio Kishida celebrate after Suga was elected as new head of the ruling party at the Liberal Democratic Party's leadership election in Tokyo Reuters World news in pictures 13 September 2020 A man stands behind a burning barricade during the fifth straight day of protests against police brutality in Bogota AFP via Getty World news in pictures 12 September 2020 Police officers block and detain protesters during an opposition rally to protest the official presidential election results in Minsk, Belarus. Daily protests calling for the authoritarian president's resignation are now in their second month AP World news in pictures 11 September 2020 Members of 'Omnium Cultural' celebrate the 20th 'Festa per la llibertat' ('Fiesta for the freedom') to mark the Day of Catalonia in Barcelona. Omnion Cultural fights for the independence of Catalonia EPA World news in pictures 10 September 2020 The Moria refugee camp, two days after Greece's biggest migrant camp, was destroyed by fire. Thousands of asylum seekers on the island of Lesbos are now homeless AFP via Getty World news in pictures 9 September 2020 Pope Francis takes off his face mask as he arrives by car to hold a limited public audience at the San Damaso courtyard in The Vatican AFP via Getty World news in pictures 8 September 2020 A home is engulfed in flames during the "Creek Fire" in the Tollhouse area of California AFP via Getty World news in pictures 7 September 2020 A couple take photos along a sea wall of the waves brought by Typhoon Haishen in the eastern port city of Sokcho AFP via Getty World news in pictures 6 September 2020 Novak Djokovic and a tournament official tends to a linesperson who was struck with a ball by Djokovic during his match against Pablo Carreno Busta at the US Open USA Today Sports/Reuters World news in pictures 5 September 2020 Protesters confront police at the Shrine of Remembrance in Melbourne, Australia, during an anti-lockdown rally AFP via Getty World news in pictures 4 September 2020 A woman looks on from a rooftop as rescue workers dig through the rubble of a damaged building in Beirut. A search began for possible survivors after a scanner detected a pulse one month after the mega-blast at the adjacent port AFP via Getty World news in pictures 3 September 2020 A full moon next to the Virgen del Panecillo statue in Quito, Ecuador EPA World news in pictures 2 September 2020 A Palestinian woman reacts as Israeli forces demolish her animal shed near Hebron in the Israeli-occupied West Bank Reuters World news in pictures 1 September 2020 Students protest against presidential elections results in Minsk TUT.BY/AFP via Getty World news in pictures 31 August 2020 The pack rides during the 3rd stage of the Tour de France between Nice and Sisteron AFP via Getty World news in pictures 30 August 2020 Law enforcement officers block a street during a rally of opposition supporters protesting against presidential election results in Minsk, Belarus Reuters World news in pictures 29 August 2020 A woman holding a placard reading "Stop Censorship - Yes to the Freedom of Expression" shouts in a megaphone during a protest against the mandatory wearing of face masks in Paris. Masks, which were already compulsory on public transport, in enclosed public spaces, and outdoors in Paris in certain high-congestion areas around tourist sites, were made mandatory outdoors citywide on August 28 to fight the rising coronavirus infections AFP via Getty World news in pictures 28 August 2020 Japanese Prime Minister Shinzo Abe bows to the national flag at the start of a press conference at the prime minister official residence in Tokyo. Abe announced he will resign over health problems, in a bombshell development that kicks off a leadership contest in the world's third-largest economy AFP via Getty World news in pictures 27 August 2020 Residents take cover behind a tree trunk from rubber bullets fired by South African Police Service (SAPS) in Eldorado Park, near Johannesburg, during a protest by community members after a 16-year old boy was reported dead AFP via Getty World news in pictures 26 August 2020 People scatter rose petals on a statue of Mother Teresa marking her 110th birth anniversary in Ahmedabad AFP via Getty World news in pictures 25 August 2020 An aerial view shows beach-goers standing on salt formations in the Dead Sea near Ein Bokeq, Israel Reuters World news in pictures 24 August 2020 Health workers use a fingertip pulse oximeter and check the body temperature of a fisherwoman inside the Dharavi slum during a door-to-door Covid-19 coronavirus screening in Mumbai AFP via Getty World news in pictures 23 August 2020 People carry an idol of the Hindu god Ganesh, the deity of prosperity, to immerse it off the coast of the Arabian sea during the Ganesh Chaturthi festival in Mumbai, India Reuters World news in pictures 22 August 2020 Firefighters watch as flames from the LNU Lightning Complex fires approach a home in Napa County, California AP World news in pictures 21 August 2020 Members of the Israeli security forces arrest a Palestinian demonstrator during a rally to protest against Israel's plan to annex parts of the occupied West Bank AFP via Getty World news in pictures 20 August 2020 A man pushes his bicycle through a deserted road after prohibitory orders were imposed by district officials for a week to contain the spread of the Covid-19 in Kathmandu AFP via Getty World news in pictures 19 August 2020 A car burns while parked at a residence in Vacaville, California. Dozens of fires are burning out of control throughout Northern California as fire resources are spread thin AFP via Getty World news in pictures 18 August 2020 Students use their mobile phones as flashlights at an anti-government rally at Mahidol University in Nakhon Pathom. Thailand has seen near-daily protests in recent weeks by students demanding the resignation of Prime Minister Prayut Chan-O-Cha AFP via Getty World news in pictures 17 August 2020 Members of the Kayapo tribe block the BR163 highway during a protest outside Novo Progresso in Para state, Brazil. Indigenous protesters blocked a major transamazonian highway to protest against the lack of governmental support during the COVID-19 novel coronavirus pandemic and illegal deforestation in and around their territories AFP via Getty World news in pictures 16 August 2020 Lightning forks over the San Francisco-Oakland Bay Bridge as a storm passes over Oakland AP World news in pictures 15 August 2020 Belarus opposition supporters gather near the Pushkinskaya metro station where Alexander Taraikovsky, a 34-year-old protester died on August 10, during their protest rally in central Minsk AFP via Getty World news in pictures 14 August 2020 AlphaTauri's driver Daniil Kvyat takes part in the second practice session at the Circuit de Catalunya in Montmelo near Barcelona ahead of the Spanish F1 Grand Prix AFP via Getty World news in pictures 13 August 2020 Soldiers of the Brazilian Armed Forces during a disinfection of the Christ The Redeemer statue at the Corcovado mountain prior to the opening of the touristic attraction in Rio AFP via Getty World news in pictures 12 August 2020 Young elephant bulls tussle playfully on World Elephant Day at the Amboseli National Park in Kenya AFP via Getty World news in pictures 11 August 2020 French Prime Minister Jean Castex is helped by a member of staff to put a protective suit on prior to his visit at the CHU hospital in Montpellier AFP via Getty World news in pictures 10 August 2020 Locals harvest their potatoes as Mount Sinabung spews volcanic ash in Karo, North Sumatra province, Indonesia Antara Foto/Reuters World news in pictures 9 August 2020 Doves fly over the Peace Statue at Nagasaki Peace Park during the memorial ceremony held for the 75th anniversary of the atomic bombing EPA World news in pictures 8 August 2020 Anti-government protesters try to remove concrete wall that installed by security forces to prevent protesters reaching the Parliament square, during a protest against the political elites and the government after this week's deadly explosion in Beirut AP World news in pictures 7 August 2020 A protester throws a stone towards Israeli forces in the village of Turmus Aya, north of Ramallah in the occupied West Bank, following a march by Palestinians against the building of Israeli settlements AFP via Getty World news in pictures 6 August 2020 A woman yells as soldiers block a road for French President Emmanuel Macron's visit the Gemmayzeh neighborhood. The area in Beirut suffered extensive damage from the explosion at the seaport AP World news in pictures 5 August 2020 Damage at the site of Tuesday's blast in Beirut's port area, Lebanon Reuters World news in pictures 4 August 2020 A large explosion in the Lebanese capital Beirut. The blast, which rattled entire buildings and broke glass, was felt in several parts of the city AFP via Getty World news in pictures 3 August 2020 A general view shows the new road bridge in Genoa, Italy ahead of its official inauguration, after it was rebuilt following its collapse on August 14, 2018 which killed 43 people Reuters World news in pictures 2 August 2020 Empty stall spaces are seen hours before a citywide curfew is introduced in Melbourne, Australia EPA World news in pictures 1 August 2020 People take part in a demonstration by the initiative "Querdenken-711" with the slogan "the end of the pandemic - the day of freedom" to protest against the current measurements to curb the spread of COVID-19 in Berlin, Germany AFP via Getty World news in pictures 31 July 2020 Pilgrims circumambulating around the Kaaba, the holiest shrine in the Grand mosque in Mecca. Muslim pilgrims converged today on Saudi Arabia's Mount Arafat for the climax of this year's hajj, the smallest in modern times and a sharp contrast to the massive crowds of previous years Saudi Ministry of Media/AFP World news in pictures 30 July 2020 The Mars 2020 Perseverance mission lifts off at the Kennedy Space Centre in Florida. The mission is part of the USA's largest moon to Mars exploration. Nasa will attempt to establish a sustained human presence on and around the moon by 2028 through their Artemis programme EPA World news in pictures 29 July 2020 A woman refreshes herself in a outdoor pool in summer temperatures in Ehingen, Germany dpa via AP World news in pictures 28 July 2020 Malaysia's former prime minister Najib Razak speaks to the media after he was found guilty in his corruption trial in Kuala Lumpur AFP via Getty World news in pictures 27 July 2020 North Korean leader Kim Jong Un poses for a photograph after conferring commemorative pistols to leading commanding officers of the armed forces on the 67th anniversary of the "Day of Victory in the Great Fatherland Liberation War". Which marks the signing of the Korean War armistice KCNA via Reuters

The organisation has its roots in the civil wars that convulsed Central America in the 1980s. Immigrants from El Salvador in particular headed north, coalescing into MS-13 in Los Angeles in part as a way to defend against entrenched Mexican-American gangs. “The Tapeworm” was a member of a Los Angeles clica, or local branch.

A wave of deportations followed. But rather than neutralise the organisation, law enforcement officials say, the wave of hardened returnees replenished and fortified its Central American base.

“You have MS-13 members who would be convicted for crimes, spend time in California prisons, be deported, and they would return almost as heroes”, said Robert Clifford, who directed a national MS-13 task force for the FBI and relayed the story about the flagless MS-13 member, told to him by a Honduran official who was visiting Washington.

Well over a decade after Newsweek ran a story warning of “The Most Dangerous Gang in America”, MS-13 has only grown more formidable. A government-backed truce between El Salvarodan gangs, now widely viewed as a misstep, helped the gang assert more control and become what researchers call a quasi-government in much of the region.

ICE director calls Oakland mayor 'gang lookout' for immigration raid warning

The consequences of those developments have reverberated from Tegucigalpa to New England. Spiralling violence has again propelled people to the United States. “There are literally, for most of those kids, zero options. You have the gangs or nothing,” said researcher Douglas Farah.

Law enforcement officials in the United States have noted a spike in crime linked to MS-13 – and it is often horrific. Thomas Manger, chief of police in Montgomery County, Maryland, testifying to Congress last summer said a “dramatic” increase in MS-13 members in local jails and prisons and noted that they were often incarcerated for crimes, like stabbings and beatings, distinguished by “premeditation, brutality and callousness”.

As the gang violence feeds calls for an immigration crackdown, there are signs of the old cycle repeating itself. A 2017 paper co-authored by Mr Farah warned that Central American gangs were “already beefing up their ranks due to the recent influx of gang members being deported from the United States”.

“The illusion you’re somehow going to arrest your way and deport your way out of MS-13 being in the United States is a dangerous fantasy”, Mr Farah said.

That isn’t to say that law enforcement officials are arguing against removing the most dangerous offenders. Deportation, Mr Clifford said, remains “the most immediate and strongest tool” for law enforcement. But it cannot be the only one.

“That’s the million dollar question, trying to find the balance”, said Scott Conley, a detective and gang investigator in Chelsea, Massachusetts.

“Deportation alone won’t solve the problem,” he added. “It has to be coupled with sophisticated criminal investigations.”

Law enforcement officials suggest a variety of tactics that may be more effective. Some advocate the kind of elaborate racketeering cases that were used to dismantle the mafia, with more federal prosecutors to help build them. Congress could fund more regional gang task forces. Better information-sharing between the US and Central American countries could help, including by allowing the governments of El Salvador, Honduras and Guatemala to prepare for deportees.

“That way when that plane lands they’re aware there’s an individual on it that has gang ties or gang-related offences,” Mr Conley said, pointing to an FBI initiative called the Transnational Anti-Gang task force.

But law enforcement officials and migration experts concede that deportation and prosecution cannot cure the underlying factors empowering MS-13. A comprehensive approach would require strengthening civic institutions in Central America – and perhaps more critically, preventing young immigrants in America from being coerced into joining.

“The unaccompanied minors that come into our country are particularly vulnerable to gang recruitment,” Mr Manger said, noting that MS-13 will often threaten peoples’ families back home.

That requires the resources to support recent arrivals from Central America, many of whom arrive knowing few people and with little structure to guide them. It is not uncommon for people to have endured trauma, Mr Conley said, pointing to a “serious mental health crisis”.

“In El Salvador it’s far more complex. It’s generational. Somehow everyone’s touched negatively [by gang violence],” he said.

Part of the solution, law enforcement officials say, is ensuring immigrants who may be in the country illegally are not afraid to talk to the authorities. While Mr Trump has railed against so-called “sanctuary” laws that limit interaction between local police and Immigration and Customs Enforcement, saying they make America unsafe, officials in hubs of MS-13 violence say they need lines of communication to remain open.

“We have to create an environment in which undocumented individuals feel comfortable coming to law enforcement with information about crimes,” then-Suffolk County police commissioner Timothy Sini, who has since been elected district attorney, told Congress in May 2017, explaining why his jurisdiction did not participate in a federal initiative delegating immigration enforcement powers to local law enforcement.

The other part, Mr Sini said, must be coupling targeted enforcement with investment in “community-based programmes to reduce gang recruitment and gang enlistment”.

“If we do not provide the structure for these young people,” he said, “MS-13 will.”

An approach that spans multiple hemispheres is an ambitious one. But people who have been on the frontlines of battling MS-13 say that it is critical to breaking the pattern of violence and migration.