Trump's DHS appointees have dismantled civil rights protections, allowed agents to remain anonymous, and encouraged them to wear masks.
They have also threatened groups that opposed them and overwhelmed legal challenges to their arrests and tactics.
Recordings of emergency calls captured the terror residents felt as they watched masked men ambush people and force them into unmarked cars.
ProPublica, a nonprofit newsroom, investigates abuses of power and reports on these incidents.
Author's summary: Trump builds repressive police force.