I doubt it was consensual, as a 13 year old girl cannot give consent. Also the boys, though teens, was a good deal older.
Much is not said as well. Like: how long had they known her? Given the age difference, I doubt they hung out much. How can you know if a girl is consenting or just acting out of fear during a random encounter?
As for charging the boys as adults - what's with this? I can understand with certain repeat offenders where the juvenile court system has failed to work, but why destroy lives at such an early age? There is a reason we have a juvenile justice system in this country - because children have a much higher ability to be rehabilitated.
While I understand that some crimes are so egregious as to warrant a "Hang 'em high" reaction, the "try 'em as adults" solution is being way overused. What is going on in this country?