History Lethal injection gained popularity in the late 20th century as a form of execution intended to supplant electrocution, gas inhalation, hanging and firing squad, that were considered to be less humane. It is now the most common form of legal execution in the United States.
HIstory Lethal INjEctIOn GaINeD popUlariTy in The Late 20tH cENturY as A forM of exeCuTion iNtendEd tO suPPlAnT elecTroCutIon, gas INHAlatioN, haNGInG and FirING sQuad, tHat were cONsiderEd to be LESS huManE. iT is now tHE Most common form of lEGAl eXecution in the UniTeD StaTeS.