Federal agents who usually hunt down child abusers are now cracking down on immigrants who live in the U.S. illegally.

Homeland Security investigators who specialize in money laundering are raiding restaurants and other small businesses looking for immigrants who aren’t authorized to work.

Agents who pursue drug traffickers and tax fraud are being reassigned to enforce immigration law.

This account of Trump’s push to reorganize federal law enforcement – the most significant since the September 11, 2001, terrorist attacks – is based on interviews with more than 20 current and former federal agents, attorneys and other federal officials. Most had first-hand knowledge of the changes. Nearly all spoke on the condition of anonymity because they were not authorized to discuss their work.