What kind of papers do US immigration police ask when they stop you at the Mexican border heading to Mexico?

Question

What kind of papers do US immigration police ask when they stop you at the Mexican border heading to Mexico?

Answer 1

None. They just wave you in.

Answer 2

NOTHING...they just wave u in

Answer 3

nothing exept they may check your car for guns and ect

Answer 4

They check to see that your ticket is one way.

Answer 5

Nothing

Answer 6

when heading to Mexico, only by walking or driving across, the federales officers are the Adhuanas that is Mexico Federales.  They don't ask for documents, you must hit a buzzered if the light turns red you must stop and either search your vehicle or Interrogate you. When flying again the ask for the standard documentation.  Technically the issue is when you try to enter, if you have no green card or passport or US birth certificate you will not be allowed back into the US.