If you have lost count, here is a short history of what has gone wrong with the Iowa backfield. Marcus Coker and Mika'il McCall left the program, Jordan Canzeri tore his ACL, incoming freshman Greg Garmon got pinched for misdemeanor possession and now De'Andre Johnson has run into trouble. Johnson got a little rowdy at a party and the police were called.
The severity of this latest transgression seems pretty low so I wouldn't expect much disciplinary action.