First nitrogen gas execution carried out in US 

The first execution by nitrogen gas in U.S. history was carried out in the state of Alabama. Kenneth Eugene Smith, 58 years old, was put to death. The Alabama Attorney General’s Office issued a statement on this. 

“Justice has been served. Smith was put to death,” reads the statement.

Smith was convicted in 1988 of contract killing. 

Despite his appeals to the U.S. Supreme Court to halt the execution, as well as the objections voiced by the U.N. and human rights defenders, Smith was executed with nitrogen hypoxia.

The convict was administered nitrogen gas through a mask. The process took about half an hour.

This method of execution has been approved in Alabama and two other U.S. states.