Here's a rundown of several key claims made during the hearing, and our reporting on the issues and numbers referenced by officials.

Republican members of Congress hammered four Democratic mayors about their so-called sanctuary city policies, accusing them of endangering Americans and threatening to prosecute local officials.

The mayors of four so-called “sanctuary cities” faced tough questions from lawmakers about their policies toward immigrants and how they work with Immigration and Customs Enforcement at a House Oversight and Government Reform Committee on Wednesday.