Buses from America’s most controversial immigration jail roll into this border city all day long, transporting parents — and sometimes children — to starkly different fates.

Some families are deposited together at a small depot downtown, free to head to their next destination and begin new lives in the United States while they await hearings or seek asylum in the backlogged immigration courts.

But other buses take the adults alone to a forbidding black office tower nearby, where they stand in shackles and handcuffs as a federal magistrate judge rapid-fire convicts them of illegally entering the United States, virtually assuring their deportation.

Since the Trump administration announced in May it would prosecute 100 percent of all people caught crossing the border illegally — even if that meant separating parents from their children — advocates say the system has been especially overwhelmed, with haphazard results. The rules shifted again Wednesday, as President Trump signed an executive order that would end family separations but continue prosecutions, possibly meaning families would be kept in federal custody for long periods.

Migrants facing similar dangers in Central America have ended up on dramatically different paths.

Sister Norma Pimentel. (Jahi Chikwendiu/The Washington Post)

Some are “lucky,” said Sister Norma Pimentel, executive director of Catholic Charities of the Rio Grande Valley. Others, she said, are “sent to serve time.”

The disparities are most vivid in the Border Patrol’s Rio Grande sector, where the highest number of families are crossing illegally into the United States, nearly 37,000 so far this year.

Parents and children apprehended crossing the border are typically taken to Customs and Border Protection’s sprawling processing center on West Ursula Avenue, in a faded industrial park on the outskirts of town. Hundreds have been separated inside the facility, which is ringed by tall, tan fencing and uses interior chain-link fences to separate groups of detainees.

Daysi Salinas translates a transportation assistance note to fellow migrant families who were caught crossing the border, then released in McAllen, Tex., to await immigration or asylum proceedings. (Jahi Chikwendiu/The Washington Post)

Nationwide, nearly 2,500 children have been taken from their parents since mid-April, according to Homeland Security.

“It’s happening every day,” said Efren C. Olivares, racial and economic justice director at the Texas Civil Rights Project who interviews adults at the U.S. District Courthouse before they are prosecuted, typically for the misdemeanor crime of illegally entering the United States. “They’re really ramping up the numbers. This week is worse than last week.”

At the federal courthouse, 19 parents were separated at the Monday morning session. It rose to 34 by Tuesday morning, when the diverging paths unfolded on a two-block stretch of downtown McAllen, a mostly Hispanic city of 142,000.

Migrant families from Mexico and Central America who have been granted asylum are processed Tuesday in McAllen, Tex., for transport to various destinations across the United States. (Jahi Chikwendiu/The Washington Post)

Immigration officials released Marco Carias, a 41-year-old farmer from Guatemala detained for crossing the border last week in the Texas town of Roma, even though he had been deported in 2005 and could have been prosecuted for the more serious crime of illegally reentering the United States.

Carias said he hoped he was released because he has a bona fide claim for asylum. In a red shopping bag, he carried the police reports from when his son, now 17, was abducted when he was 10. The assailant had recently resurfaced and threatened the entire family.

But his records show an immigration officer released him because of a “lack of space.”

“I guess it depends on who you get,” he said before boarding a bus to California.

Federal officials also cited the space shortage when they released a 21-year-old single mother from Honduras and her 1½ -year-old son, Josua, who floated across the Rio Grande on a crowded raft last week.

She said she is seeking asylum because she fears gang violence, a criterion Attorney General Jeff Sessions recently ruled is unlikely to prevail in immigration courts.

Migrant families from Mexico and Central America at the bus depot in McAllen, Tex. (Jahi Chikwendiu/The Washington Post)

Before she left for the United States this month, she said, she had not heard that the U.S. government planned to separate parents from children and prosecute everyone who crossed the border illegally. Still, she said she would not have changed her mind.

“My life was in danger, my son’s life,” she said, holding the boy, her son, his new Spider Man sneakers tucked into her bag, as they waited for a bus to New York. “I can’t live in my country.”

The released migrants wore ankle monitors and must contend with check-ins with ICE and, eventually, hearings in immigration court. They could eventually lose their cases and be ordered deported.

But they had support from volunteers at the Catholic Charities Humanitarian Respite Center, a welcoming spot across from the courthouse where migrants can get a bowl of hot chicken soup, take a nap or watch a soccer game on a big-screen TV. Volunteers hand out razors, boxes of diapers in different sizes and fliers for the bus stop that read, “Please help me. I do not speak English. What bus do I need to take?”

A woman and her baby get ready to board a bus in McAllen. (Jahi Chikwendiu/The Washington Post)

Migrant families from Mexico and Central America wait for buses after being released to await immigration proceedings. (Jahi Chikwendiu/The Washington Post)

These migrants have a chance of staying in the United States, unlike most of the 120 or so adults who faced Magistrate Judge J. Scott Hacker on Tuesday in U.S. District Court.

Just before 2 p.m., about 50 migrants — mostly men — shuffled into the courtroom in arm and leg shackles, filling three rows of wooden benches.

The judge handled them all at once, pointing to each person as if he were a preacher at Sunday services. He asked each how they came to America. Almost everyone had crossed the Rio Grande in a boat or a rubber raft. Some swam across. One man said he walked until the water covered his head.

“I will accept all your guilty pleas,” Hacker said.

About half were sentenced to time served because they had no prior records. The rest faced more serious consequences, including a young man wearing a Yankees T-shirt who spoke perfect English because he was raised in the United States. He had been deported for drunken driving and had tried to sneak back in.

Abel Guerrero, the federal public defender, tried to speak for each one, explaining many repeat offenders were trying to join their families in Texas, North Carolina and Massachusetts.

A man with three convictions for illegally reentering the United States received 60 days in jail.

Migrant families wait in line at the bus station in McAllen. (Jahi Chikwendiu/The Washington Post)

“You should know better by now,” Hacker admonished him.

Another man had been apprehended 11 times and had two recent convictions for illegally coming to the United States.

Guerrero said the man is trying to visit his mother in Houston. “She is sick. She’s actually dying of cancer,” he told the judge. He said the woman has seven months to live.

Hacker sentenced the man to two months in jail, after which he — like the others — could be deported.

Most of the migrants had nothing to say, but three women asked when they would see their children again. After the parents and children are separated for the criminal prosecutions, the children are sent to shelters run by U.S. Health and Human Services.

“Hopefully,” the judge told one woman in response, “those officials will reunite you with your child.”