Death penalty

The death penalty, also called capital punishment is the deliberate ending of the life of a sentient being by a government. The act of carrying out the death penalty is usually referred to as execution and the person being executed was often referred to as the condemned. Throughout the history of the galaxy, many different cultures have carried out the death penalty against individuals, for a wide variety of reasons - usually for punishment for crimes such as murder and treason.

Methods
The methods used for carrying out the death penalty have varied widely throughout history.
 * Crucifixion - A method of execution carried out on Earth by a number of ancient cultures. Perhaps the most notable culture to employ this method of execution was the Roman state who considered the punishment to be a very dishonorable way to die.  Those executed by this method included Spartacus and the human religious leader Jesus Christ. (TNG novel Spartacus and VOY episode The Omega Directive).
 * Tal-Shaya - A method of execution carried out in ancient Vulcan society. The method involved breaking the neck of an individual in a way designed to cause instant death.  The ancient Vulcans considered it a merciful form of execution.  In 2268 the Tellarite Ambassador Gav was murdered on the USS Enterprise (NCC-1701) using the Tal-Shaya technique by an Orion agent.  Gav was being transported to Babel to a conference to help decide the question of admitting Coridan to the Federation.  Many Vulcans knew how to perform Tal-Shaya, and when Gav was murdered suspicion initally fell to Spock's father Sarek, also being transported to Babel before the Orion agent was exposed. (TOS episode Journey to Babel).
 * Hanging - A method of execution on Earth which involved having the condemned stand on a platform. A rope was placed around the condemned's neck and the platform was removed, or a door was opened underneath the condemned allowing him or her to drop several feet, causing death when either the person's neck was broken or when the person was asphyxiated.  Trelane considered using hanging to execute Captain James T. Kirk. (TOS episode The Squire of Gothos).
 * Gas - A method of execution in which a person was subjected to poisonous gas. This was one of the methods practiced by the Nazi government of Germany on a large scale basis to commit genocide against the Jewish people. (Historical Accounts).  The Denebians also employed it as a method of execution, and it was one of the methods offered to Harry Mudd before he escaped from Deneb V. (TOS episode I, Mudd).
 * Shooting - A method of execution in which a condemned was put to death using a weapon such as a gun or a phaser. The Denebians employed it as a method of execution, and it was one of the methods offered to Harry Mudd before he escaped from Deneb V. (TOS episode I, Mudd).
 * Lethal injection - A method of execution on Earth and other worlds in which a condemned was put to death by having a lethal concentration of chemicals injected into them. Prior to implanting memory engrams of a murder victim into the mind of the person convicted their murder, the Banean executed them by lethal injection. (VOY episode Ex Post Facto).