That is one heck of a mistake; or was it intentional?
"Border Patrol officials are investigating an incursion by Mexican federal police into the United State on Thursday morning.
U.S. Border Patrol spokesman Doug Mosier said armed officers with Mexico's Secretaria de Seguridad Publica federal police were in the incursion, which took place in El Paso, near the Border Patrol's Ysleta station.
The Mexican government, Border Patrol and Texas Parks and Wildlife Department are investigating the incident. U.S. authorities responded to the incident."