Broken lives of immigrants deported from US to Mexico
20 March 2014 Last updated at 00:57 GMT
Almost two million undocumented immigrants have been deported from the US since Barack Obama entered the White House, more than under any previous president.
Under pressure from Hispanic politicians, Mr Obama last week announced a review of his administration's deportation policy, promising to enforce immigration laws "more humanely".
Many of those sent back to Mexico have to walk through a door in the fence separating California and the Mexican town of Tijuana. Some were caught trying to enter the US illegally, others had lived in the US - without papers - for years.
Officially they are being sent "home", but often deportation means being separated from families still in the US and starting a new life from scratch.
The BBC's Valeria Perasso reports from both sides of the border on what happens to deportees once they pass through this door.
Produced by the BBC's Franz Strasser