Why executions by firing squad may be coming back in the US

The image of gunmen in a row firing in unison at a condemned prisoner may conjure up a bygone, less enlightened era.

But the idea of using firing squads is making a comeback. Idaho lawmakers passed a bill this week seeking to add the state to the list of those authorizing firing squads, which currently includes Mississippi, Utah, Oklahoma and South Carolina.

Fresh interest comes as states scramble for alternatives to lethal injections after pharmaceutical companies barred the use of their drugs.

Some, including a few Supreme Court justices, view firing squads as less...