My Border Patrol Diary by Dale Squint is a raw, unfettered account of life on the edge of Texas. http://www.amazon.com/books/dp/1434325059
"There was a program in operation, at least in our sector, where a rancher/farmer was able to 'keep' an illegal or illegals on his ranch or farm legally. It was called the 'D-5' program. A 'D-5' was an illegal alien. He was probably a very good worker and was liked by the individual rancher/farmer. The border patrol would allow this rancher/farmer to 'keep' this illegal on his ranch, and in return we expected information...."