OKLAHOMA CITY (Reuters) - Oklahoma Governor Mary Fallin on Friday signed into law a bill that allows the use of nitrogen gas as an execution method if the U.S. Supreme Court determines that the state's current lethal injection process is unconstitutional or unavailable.
Fallin, a Republican who supports capital punishment, said she believes executions must be performed effectively and without cruelty and the bill gives Oklahoma another death penalty option that meets that standard.
The state's three-drug method of capital punishment has been under scrutiny since the flawed execution of an inmate in April 2014 whose intravenous line was improperly placed by death chamber staff.
If the lethal injection method is not available, nitrogen hypoxia becomes the alternate method of execution, followed by the electric chair and a firing squad as a fourth alternative.
The nitrogen method of execution would require an inmate to be placed in a sealed chamber or to wear a special mask. The process would involve slowly replacing oxygen with nitrogen.
Republican state Representative Mike Christian, the bill's author, has said the process would be painless for inmates and affordable for Oklahoma.
The state Senate approved the bill without opposition in April and the state House of Representatives voted 85-10 to advance the bill in March.
(Reporting by Heide Brandes; Writing by David Bailey; Editing by Eric Beech and Doina Chiacu)