- Alabama inmate Kenneth Smith executed with nitrogen gas, marking the emergence of a wholly new method of capital punishmentCNN
- Alabama Executes Kenneth Smith by Using Nitrogen, a First in the U.S.The New York Times
- EU Slams ‘Particularly Cruel’ US Nitrogen ExecutionBarron’s
- Alabama death row inmate executed with nitrogen gas, nation’s first by a new method in 42 yearsFox News
- Kenneth Eugene Smith executed by nitrogen hypoxia in Alabama, marking a first for the death penaltyCBS News