(CNN)On your 18th birthday, immigration officials will come for you, a lawyer explained. You will be shackled, you will be placed in an orange jumpsuit, and you will be taken to jail. "But I need you to know you are not a criminal."
For unaccompanied minors, countdown to 18th birthday is filled with fear and dread
This is how Allison Norris, toll litigation staff attorney at Americans for Immigrant Justice, prepares her teenage clients in federal migrant detention shelters who are nearing age 18 without the prospects of a suitable sponsor to whom they can be released.
One of these clients is Veronica, whose name has been changed to protect her identity for fear of retribution. At age 17, she arrived in the United States alone, fleeing sexual predators in El Salvador.
Between the time Veronica arrived and when she turned 18, just over four months, Norris says, she attempted to find a sponsor. But none of the family friends who applied met the extensive list of requirements of the Office of Refugee Resettlement in order for her to be released from the shelter for migrant children in South Florida where she was detained.
On her 18th birthday, she woke up scared, wondering what would happen to her, Veronica said. Norris' detailed warnings had not exactly calmed her down.
At 8 a.m. on her birthday, immigration officials arrived at the shelter. She was placed in ankle shackles and put in a "very cold room" for hours before being taken into adult detention, Veronica said.
In the months that followed, Veronica describes feeling depressed, crying every day and losing hope. Because she wasn't serving a specific sentence, she had no idea how long she'd spend in detention.
With hours to fill in a cell she shared with three older women, she relived in her mind the attacks she suffered in El Salvador.
"I didn't know what was worse: to have died in El Salvador or to be locked up," she said.
Veronica is part of a group of kids known as ORR age-outs. When unaccompanied minors arrive in the United States, they are placed in the custody of the Office of Refugee Resettlement, part of the US Department of Health and Human Services, a humanitarian agency in nature.
Once they turn 18, teens are moved into the custody of the Department of Homeland Security -- more specifically, US Immigration and Customs Enforcement, a law enforcement agency known as ICE. Migrant youth cannot, by law, stay in the shelters that housed them before they turned 18.
"I have interviewed the children right before they turn 18 and they go into these facilities," said Yenis Castillo, a forensic psychologist with the nonprofit advocacy group Physicians for Human Rights. "All the kids I interview are terrified."
In the weeks leading up to their 18th birthdays, Castillo said, she has seen teens act out, develop chronic headaches or high blood pressure, become depressed and even become suicidal.
"When people undergo trauma, they live in a constant state of alert, and on top of that, then we are sending them to prison," she said.
Neha Desai, director for immigration at the National Center for Youth Law, has toured immigrant child detention centers across the country. "Everywhere I go, the kids that are in most extreme and visible distress are the ones that are approaching age-out. There's so much anxiety in that period of time," she said.
The Trafficking Victims Protection Reauthorization Act, passed in 2000 and reauthorized in 2008 and 2013, states that when unaccompanied immigrant children in the custody of the Office of Refugee Resettlement t