Horizon -- How to Kill a Human Being Tuesday 15 January, 9pm, BBC Two Former Conservative MP, Michael Portillo pushes his body to the brink of death in an attempt to discover a method of executing criminals that is fundamentally humane in How to Kill a Human Being - the first programme in a new series of BBC Two's Horizon. It is an investigation that will take us into the darkest reaches of science. Across the world capital punishment is in crisis. In Vietnam shaky marksmen have brought into serious question the reliability of the firing squads. In Iraq Saddam's half brother was hanged and decapitated by mistake. And in the United States -- the most technologically advanced nation in the world -- the use of their primary method of execution, lethal injection, has ground to a halt as the Supreme Court examines whether prisoners are actually dying in unnecessary pain. Michael looks to science to find a better solution and explore the key execution methods still available today. He discovers why convicts can catch on fire in the electric chair, how easy it is to botch a hanging and explores the terror of the gas chamber. Armed with the startling evidence he uncovers, Michael sets out to establish what he believes are the criteria for a perfect humane execution. As he does so he sets his sights on a wholly new method, utilizing a biological phenomenon known as hypoxia -- the lack of oxygen to the brain. Could it be the solution?