Rape and Punishment

[sesame]

Rape: the nature of the offence is such that the injury is much deeper in the emotional level than the physical. The anger and pain in the mind often accelerates more and more with frustration, even though years have past and the body has healed. There is no excuse of forcibly taking control of another persons body for the momentary pleasure and satisfaction of the offender.
Shame and social guilt of the victim and pressure from the relatives and friends often let the guilty party escape punishment. The mental agony of the victim in such cases is unbearable.
Let go of primitive societies, even in modern metro cities this crime claims many victims. And in most of the cases, the charges are dropped!!! Whatever the reasons may be. Perhaps technical fault of the CSI, or the medical exam was performed too late or the sample DNA was corrupted or most commonly, the victims withdrew the charges being threatened or too ashamed.
What should the proper punishment be for such a crime?