The BBC's Timeshift Series - Series 10 - No.9 - Crime and Punishment: the story of capital punishment is a thought-provoking film. The whole film is just short of 1 hour in duration and the first 44 minutes traces the history of the death penalty in the UK and the movement for its abolition. After that, the film turns to look at the situation in the USA and elsewhere.
Within Council of Europe member states the death penalty is abolished under Protocol 13 to the European Convention on Human Rights. Amnesty International has an up-to-date summary of the world wide position.