There’s been a lot of action coming out of Washington, D.C., this week on the issue of immigration. President Trump has signed executive orders to withhold federal money from so-called sanctuary cities and to get started building a wall on the country’s border with Mexico.

His administration has also been talking about ways to pay for that wall. He campaigned on a pledge that Mexico would foot the bill. One idea is to implement a 20 percent tax on all imports coming in from Mexico.

There are already barriers on parts of America’s southern border, different kinds in different places.

That’s something Andrew Becker’s been looking in to. Becker is with Reveal from the Center for Investigative Reporting.