There's the firing squad, the electric chair... and now, the gas chamber. Conservative US states, facing difficulties around lethal injections, are looking to the past for alternative ways to carry out executions of their death row inmates. On Tuesday, the Arizona state Supreme Court set June 8 for the execution of Frank Atwood, sentenced to death in 1987 for the murder of an eight-year-old girl. He was given two weeks to choose between lethal injection or being gassed with lethal chemicals. According to his lawyer, prison authorities in the southwestern state are considering using hydrogen cyanide, the main component of...