Executions in the US have come to a standstill ahead of a Supreme Court hearing today that will consider the constitutionality of the lethal injection method of execution used by most states.

For the first time in more than a century, the top court will consider whether a particular method of execution violates the constitution’s prohibition on “cruel and unusual punishment”. The case, which examines executions in Kentucky, is part of a broader Supreme Court re-appraisal of the death penalty, which has recently included rulings stopping the executions of juveniles and the mentally impaired. Last week the justices also agreed to decide whether it is constitutional to impose the death penalty for child rape.