Islam's rulings regarding stoning, execution, and cutting the fingers are each addressing very peculiar situations and are extremely difficult to prove. They are only applicable if all of their requirements and conditions are present. Otherwise, they are indeed inapplicable. The prerequisites for execution and stoning are so much difficult so that they may very seldom establish. Basically, there is a rule in Islamic jurisprudence, according to which the application of Islamic punishments must be stopped in the event of any slight doubt or suspicion.
Furthermore, those punishments which only have public aspects can be stopped by the discretion of the Islamic government, if it is truly elected by the free participation of the people.
[Note: Within Islamic jurisprudence certain crimes are only subject to prosecution upon the initiation of another individual. For example, if someone claims that another has committed adultery but cannot prove it, this is a "crime" of defamation and is punishable by 80 lashes. However this offense is only subject to prosecution if the offended party wants justice. If the offended party abandons prosecution, the judiciary cannot prosecute.
However, most other crimes also enjoy a public nature. For example, murder in Islam is subject to both private and public grounds for prosecution. Therefore, if the injured private party stops prosecution, the judiciary will still proceed to satisfy the public aspect of punishment for murder.
A crime like adultery only has a public aspect. Prosecution for adultery is not initiated by a private party. The judiciary initiates the prosecution. The Ayatollah in this fatwa avers that in crimes such as this the government has the discretion to suspend the implementation of punishment if necessary.]
[For other opinions on this topic search: punishments.]
احكام رجم ، اعدام و قطع عضو هركدام موضوع خاصى و شرايط ويژه اى دارد كه اگر آن شرايط كاملا محقق باشد قابل اجرا خواهد بود، وگرنه نمى توان آنها را اجرا نمود. شرايط رجم و اعدام آن قدر زياد و سخت است كه بندرت ممكن است تحقق پيدا كند، و اصولا در مجازاتهاى اسلامى قاعده اى وجود دارد كه اگر در تحقق بعضى شرايط آنها از نظر موضوع يا حكم شبهه و شكى وجود داشته باشد نبايد مجازات مربوطه اجرا گردد. همچنين در مجازاتهايى كه جنبه حق الناس در بين نباشد و مربوط به حقوق جامعه باشد حاكميت صالح و منتخب مردم مطابق صلاحديد و شرايط مقتضى مىتواند مانع از اجراى آنها شود.