Where’s this guidance come from?

It is a blueprint to implement executive orders that Mr Trump signed on 25 January, days after taking office.

The new guidelines did not explain how Mr Trump’s border wall would be funded and where undocumented immigrants apprehended in the crackdown would be detained.

The memos instruct agents to use “all available resources to expand their detention capabilities and capacities”, but Congress would probably need to allocate money to build new detention centres.