When someone is found guilty of a crime, there is a completely separate hearing in which they are actually sentenced to a specific punishment. Different facts of the case and the individual involved in the case are taken into account at this point to see how a person should be punished for any specific crime. A judge will determine a sentence on the basis of these facts.
Of course, judges are not meant to pick just any sentence for the crime that has been committed. There are federal sentencing guidelines that give them a model for what kinds of crimes are punishable by what kind of a sentence. Judges have to consult these guidelines before choosing a sentence and can determine where in the range of sentences this case falls.