I went undercover and volunteered for an NGO, which is short for non-government organization, typically a nonprofit. You've probably seen NGOs on the news without even knowing it. These are the organizations reporters try to get into with locked doors.
Besides getting in, I took on multiple roles as a volunteer. I was there when they helped asylum seekers with their paperwork, airport transfers, and getting them through TSA.
With the videos and documents I have, it quickly becomes clear just how many gaps there are in the system after someone illegally enters the southern border, including their redistribution to various cities.
Most people investigating the process started at the border and have tried to follow the story from there. I started in a "sanctuary city" and worked my way south.