How is the death penalty - as stated in Islamic law - implemented? Is it by hanging or beheading?

The method of executing a death sentence issued by a Sharia court varies according to the type or reason for the ruling.

Firstly: Stoning (Rajm): This is for the married fornicator and for the crime of sodomy according to the majority of scholars. The perpetrator and the one upon whom the act is committed are stoned according to the Malikis and Shafi'is, whether they are married or not.

Secondly: Killing by Retaliation (Qisas): The Malikis, Shafi'is, and a narration from the Hanbalis hold that the killer is retaliated against with the same method and instrument by which he killed, unless the method is forbidden. The Hanafis and the prevalent opinion among the Hanbalis hold that Qisas is only carried out by the sword to the neck, regardless of the instrument or method.

Thirdly: Killing by the Sword: 1. As a Hadd (prescribed punishment): This is for killing an apostate. 2. As a Ta'zir (discretionary punishment): Ta'zir may reach the level of killing if the public interest necessitates it, such as killing a Muslim spy, or one who promotes innovation (bid'ah), or one whose corruption cannot be removed except by killing. The reason for using the sword in most cases is to perform the killing in the best possible manner, based on the Prophet's (peace be upon him) saying: "When you kill, do it in the best possible way."