State of Utah uses firing squad to execute a killer. any comments?

Its been 14 years, since the State of Utah has used a firing squad to execute a convicted killer for a capital crime. anonymous police officers volunteered to carry-out the execution of Ronnie Lee Gardner for using a weapon to kill two people. only one officers rifle had the actual live bullit that completed the task. Question: in your opinion, how does the use of a firing squad execution to you, compare to the use of lethal injection, gas, or the electric chair? is one more humane than the other?

Source: Associated Press.