The proposed law of castrating rapists has a basic flaw in it given that it is to be implemented in Pakistan. The rapist will bribe the doctor who will issue a false certificate that castration has been carried out. This is particular to Pakistan as no one can be trusted here shown by experience. The better law would be to first castrate the culprit and after one week hang him in public. Only this can ensure transparent justice and prove a deterrent against the crime.
Have you read the proposed law? I haven't.
Anyways, I assume the castration will be for repeat offenders and when judge deems that the person is not violent otherwise, and such judgment will be rather based on psychological analysis.
Death penalty for rapists is not a so straightforward issue.
The issue of rape involves two or more unrelated factors but those cannot be easily separated.
The first is uncontrollable sexual urge or opportunity or social or sub-cultural pressure
The second is violence, exploitation and authority.
Further some individuals are sadistic, abnormal or have psychological issue.
Influence of drugs or alcohol is another factor.
Only a fair trail can help assess of the nature of the rape crime. However the aim of the law is to control the crime as much as possible (rape cannot be eliminated). However deterrence shouldn't be the sole criteria and rehabilitation should be considered. Not to forget that bulk of the rape occurs within families, quittance and friends - in several such situation it is not always easy to assess the bulk of the blame.
Death/hanging will be, of course, very rare and for heinous acts only extreme cruelty involving death or a minors abuse besides rape or for the leaders of gangs for rape. etc.
Blanket death penalty for rapists is not practical or desirable
- first the rape is a common and a widespread crime
- second the mandatory death penalty will require strict proofs and evidence and many rapist will be acquitted than punished.
- third most rapes are within family and friends, death penalty means more crimes will not come to court with lesser chance of collaborating witnesses.
- fourth, death penalty will result in more chances of murder of the victim, If the rapist fears death in case being caught, he will do all to eliminate the evidence -- the last one is main argument for opposing death penalty for rapists ; that is to save the victims.