Republican lawmakers confronted the Democratic mayors of four “sanctuary cities” over immigration policies that they believe have shielded criminal immigrants in the United States illegally, placing Americans and federal officers at risk.

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

Denver Mayor Mike Johnston will soon be on his way to Washington D.C. to testify before the U.S House Oversight and Government Reform Committee to explain the city’s “sanctuary jurisdiction” policies.