They want a lethal injection?
The DEA seizes lots of heroin.
Provide a supply to the States that have executions.
Inject a massive overdose.
Criminal will pass out and die.
...Also demonstrates to the public how deadly heroin can be.
Cry me a river!
Nitrogen asphyxiation
To all those here who incessantly harp for tortuous means of execution remember that the means of execution says more about the civilization than the crime.
Our founders knew this.
That said....a proper long drop hanging is sound.
Technically though gruesome....the guillotine is fail proof with proper weighted and sharpened blade
France executed 10,000s with rarely a malfunction...none if machine properly maintained
Burma used elephant foot crush.....other SE Asians did too..
Likely foolproof as well but PETA would howl
BRING BACK OL' SPARKY!