List of botched executions
A botched execution is defined by political science professor Austin Sarat as: Botched executions occur when there is a breakdown in, or departure from, the 'protocol' for a particular method of execution. The protocol can be established by the norms, expectations, and advertised virtues of each method or by the government's officially adopted execution guidelines.
Source: Wikipedia — List of botched executions (CC BY-SA 4.0)