An article from the Washington Post tells us

• Most hard drugs the come to the US from Mexico enter via ports of entry, not open sections of the border
• The Guzman (El Chapo) trial detailed methods used including inside railroad tanker cars, trucks and even a submarine.

www.washingtonpost.com

Also here was a story from the El Paso Times

Analysis: 'El Chapo' trial shows why wall won't stop drugs from crossing US-Mexico border

The trial is a telenovela-style explainer on why a wall is unlikely to stop the lucrative U.S.-Mexico drug trade.

El Paso Times