Based on your information you can certainly pursue U visa which is intended with an option to protect the victim of violence regardless of their immigration status. Only important thing in u visa package is the law enforcement officer (it could be the police officer or the prosecutor)....Robbery is certainly a qualifying crime. Please read the following article it has some information on numbers and data...
http://america.aljazeera.com/articles/2014/1/23/family-saga-revealsforcedmarriageimmigrationfraudandmurder.html


Bandita Sharma Dahal, Esq.


http://www.philadelphiaimmigration.co/