Members of the Northern Virginia Regional Gang Task Force, partnered with ICE officers, walk in force toward a house in Manassas, Va., to arrest a suspected MS-13 gang member in August. (Melina Mara/The Washington Post)

A convoy of black vehicles converged on a suburban house in Manassas, Va., on a Thursday evening in August. Burly men in bulletproof vests — members of the Northern Virginia Regional Gang Task Force — approached a scrawny 20-year-old from El Salvador as he talked on his cellphone in the driveway.

“Alexander Ceron?” one of the men asked.

Three years earlier, Ceron had been among the thousands of unaccompanied minors who surged across the U.S. border, fleeing gang violence. He had been detained at the border and then released to his father while his asylum case moved through the backlogged immigration court system. For a time, he’d starred on the soccer team at Stonewall Jackson High School, and he’d attended all of his immigration hearings.

But police suspected Ceron was a member of MS-13, the violent street gang that has made a comeback in the United States, with dozens of grisly killings in the Washington region, on Long Island and in Boston and Houston.

Authorities didn’t have evidence to criminally charge Ceron. So instead of a police officer, it was an agent from Immigration and Customs Enforcement who slapped the handcuffs on his wrists for being in the country illegally. Ceron has an immigration hearing later this month.

The Aug. 10 arrest is part of the Trump administration’s countrywide crackdown on ­MS-13 — a push that has raised legal questions even as it yielded more arrests.

In President Trump’s first five months in office, ICE investigators arrested 311 alleged MS-13 members on a variety of ­charges, nearly twice the rate during the 16 months before he took office, according to statistics from Homeland Security Investigations, a branch of ICE. Those same statistics show the number of arrests of alleged MS-13 members only for immigration violations like Ceron’s has more than quadrupled.

Matt Allen, ICE’s assistant director for investigative programs, said picking up suspected gang members for immigration violations instead of criminal violations gets them off the streets before they can commit crimes.

“We certainly don’t need to wait for them to accumulate criminal convictions before taking them out of circulation using our civil immigration authority,” Allen said.

In MS-13 hotspots, like the Washington area and Long Island, ICE agents now routinely embed with local law enforcement, Allen said. If suspected gang members can’t be arrested on criminal charges but are undocumented, they will be arrested administratively.

“That kind of a posture is new,” Allen said. “Going out and operating with a local gang unit, seeing what they see, and having our tool in their toolbox by having an ICE [agent] with them.”

ICE points to the case of Omar Antonio Villalta, 22. HSI agents arrested the Salvadoran during a traffic stop in Sterling, Va., on July 5. Villalta had no criminal history but was arrested for being in the country illegally.

While in ICE custody, Villalta was linked to a quadruple homicide in Long Island, where police say MS-13 hacked to death four young men before burying their remains in a park earlier this year. Nicknamed “Anticristo,” Villalta has been charged with four counts of murder in a federal court in New York. His attorney did not respond to a request for comment.

But immigration attorneys and advocates argue many of these administrative arrests are illegal. Much of the criticism centers on the arrests of immigrants who arrived as unaccompanied minors, like Ceron.

Over the past four years, more than 170,000 of these children have been detained at the border and reunited with family members in the United States by the Office of Refugee Resettlement, a branch of the U.S. Department of Health and Human Services.

Since Trump took office, ICE has begun administratively rearresting some of these unaccompanied minors, often shortly after they turn 18, or “age out” of the ORR program, making it easier to detain and deport them. In many cases, ICE claims they have joined MS-13.

“What we’ve learned is that there is a fairly good correlation between the increase in unaccompanied minors that started in 2014 and MS-13 recruitment,” Allen said.

Northern Virginia Regional Gang Task Force officers question suspected gang members in Manassas on an August evening. (Melina Mara/The Washington Post)

A Washington Post investigation published in June found that a surge in MS-13 violence was linked to the gang’s enlistment of children from El Salvador, Honduras or Guatemala who had crossed the border on their own.

The Washington area has one of the largest totals of unaccompanied minors in the nation: about 18,000. Many fled their countries to escape the gangs, but a small number fall prey to them in the United States.

The Post investigation found that at least 14 young people placed by ORR in the Washington area were involved in MS-13 violence. That includes eight charged in connection with killings.

In Suffolk County on Long Island, where MS-13 has been linked to at least 17 killings in the past 18 months, ICE has aggressively gone after unaccompanied minors it deems gang members.

Immigration attorneys and advocates argue many of these arrests are based on flimsy evidence and racial profiling.

Bryan Johnson, a Long Island immigration lawyer, represents about a dozen immigrants who arrived as unaccompanied minors and who have been labeled MS-13 members. They include a 19-year-old suspended from high school this spring for having “504” — the country code for his native Honduras — on his backpack and a drawing of devil horns, both considered MS-13 symbols by law enforcement, and an 18-year-old from El Salvador who police said had been “in the presence of confirmed MS-13 members on well more than four occasions,” according to an ICE memo.

“It’s like they suspended the U.S. Constitution for these kids,” Johnson said. “Getting rid of MS-13 is important. But it’s just as important to make sure that an innocent kid isn’t sent back to Central America and killed.”

ICE has also arrested unaccompanied minors before they turn 18, handing them over to ORR custody. They are not entitled to an immigration bond hearing and can spend months or even years behind bars.

Last month, the American Civil Liberties Union filed a class-action lawsuit against the Trump administration, accusing officials of “a concerted effort to arrest, detain, and transport children far from their families and attorneys, and to deny them immigration benefits and services to which they are entitled under U.S. law, based on flimsy, unreliable and unsubstantiated allegations of gang affiliation.”

ICE investigators deny the allegations and stand by the criteria used to determine if someone is a gang member, Allen said. Among the signs: gang tattoos, displaying gang signs, wearing gang apparel, frequenting an area “notorious for gangs” and being identified as a gang member by reliable sources, informants or “through reasonable suspicion.”

“It’s obviously not a reviewable determination,” Allen said, “but we use it with discretion.”

‘He had a normal life’

On a warm evening in March 2016, Alexander Ceron stepped up to take a free kick 30 yards from the goal. The slightly built Stonewall Jackson midfielder smashed the soccer ball over a wall of defenders and into the corner of the net, eliciting a roar from the crowd.

Ceron’s performance that spring earned him first team All-Conference and The Washington Post’s All-Met honorable mention.

But as he was excelling athletically, Ceron was allegedly slipping into MS-13.

He had fled his home in San Miguel, El Salvador, to escape gangs trying to recruit him, according to his father. “He was afraid that they would do something to him,” Santiago Ceron said.

At 17, Ceron struck one Stonewall Jackson educator as “extremely intelligent. And he seemed very innocent.”

But Ceron changed between his freshman and sophomore year, recalled the educator, who did not have authorization to speak and did not want to be identified. Police had briefed school employees on potential signs of gang affiliation — lines shaved in his eyebrows, bandannas on his wrists, Chicago Bulls clothing — and Ceron started displaying them.

He often didn’t show up to school. When he did, “he was known for intimidating other students,” the educator said. “He made them nervous.”

By his junior year, he was 19 and too old to play soccer under state rules. He began missing even more school.

Stonewall’s school resource officer, a Prince William County police officer, spoke to Ceron on several occasions, asking him and several friends whether they had gang ties, according to a friend, who also did not want to be identified.

Alexander Ceron, once a soccer star at Stonewall Jackson High School, is taken into custody by members of the Northern Virginia Regional Gang Task Force. He is being held in an ICE detention center in Farmville, Va. (Melina Mara/The Washington Post)

The threat of MS-13 was real. Last year, two Stonewall Jackson students were arrested and charged in separate slayings that police say are MS-13-related.

This spring, he and two friends were expelled, according to the educator and the friend. Neither knew why. Administrators at Stonewall Jackson refused to comment, citing privacy restrictions.

After his expulsion, Ceron began to work for the same delivery service as his dad, loading food onto trucks in a warehouse.

“He had a [work] permit. He had a car and a driver’s license,” his father said. “He had a normal life.”

Then the task force arrived and took him away. Ceron is being held at an ICE detention center in Farmville, Va., as he awaits his hearing before an immigration judge.

Ceron’s father says Alex isn’t part of MS-13. “When he got here, I told him, ‘If you know anybody in a gang, stay away from them,’ ” he recalled. “If he got involved in something like that, I’d kick him out of my house.”

Two weeks after Ceron’s arrest, the gang task force knocked on his family’s door. Ceron’s 12-year-old brother saw the officers and went to get his dad. Before Santiago Ceron could open the door, the officers broke it open.

“They pointed their guns at my family, my kids, everybody,” he recalled. Santiago Ceron and four other men were handcuffed and made to sit on the driveway while the house was searched.

Police confirmed the incident, saying they went back to the home as part of a broader MS-13 investigation.

“Why are they coming to my house, breaking down my door and treating my whole family like criminals?” Santiago Ceron asked.

“My son is still innocent,” he said. “They haven’t proved anything yet in court.”