First time I crossed at the Sasabe, I drove past the small shack on the US side and as I approached the Mexican one-room entry post I heard gun shots. Ahead of me standing in the entry lane my Mexican border agent was target-practicing while on duty. But as I approached he holster his pistol and reloaded as I departed. On the US side, the small shack is now this lovely compound with all the 21st century Customs technology.