If the killer is executed with a sword, is it permissible for us to execute him with electricity?

The questioner : But what is your opinion if he is killed by electricity? Which is easier, the sword or electricity? The sword.

The Shaykh : Yes, it appears that electricity is easier, yes. In the name of Allah, the Most Gracious, the Most Merciful. No, if you kill [someone], they say that high voltage, like two hundred and twenty or three hundred, kills instantly,

The questioner : but it paralyzes more than the sword; it shocks first, then shocks again, meaning the sword is faster, faster,

The Shaykh : No, it is not faster; if the sword kills, the body keeps kicking until the blood runs out. But I notice this. Electricity on a chair. Yes, indeed, he does not know what is happening to himself; we ask Allah for well-being.
So it appears that if... In any case, if he is killed by electricity, he is killed by electricity, and there is no problem. But if he is killed with a sword, the requirement of retaliation (qisas) is that we kill him with a sword. And it appears that this objection you raised does not apply to the issue of retaliation.
Because the completion of retaliation is that we do to him what he did. But it applies to hirabah (armed robbery and brigandage), for example: if someone is killed in a case of highway robbery, do we kill him with a sword or with an electric shock? If we follow the saying of the Messenger (peace and blessings be upon him), "If you kill, then kill well," then we would ask the experts and say, which is better and more merciful? If they say this is more merciful, we would prefer killing by electricity.