logical deduction - How to get away with a murder

Someone is about to be executed because he killed someone and he is asked how he wants to die by a strange question:

If you say something true now, you will be executed with electricity, if you say something false you will be executed with a gun.

Then our guy says something and they could not kill him.

What could he say?

Answer

He says

"I will be killed with a gun"

So:

If the statement is true he should be killed with electricity, making it false.

If it is false he will be killed with a gun, making it true.

Hence it is a paradox and they let him go as the statement can be neither true or false.

Alternatively as @sousben points out, he could say

'You will not kill me with electricity' - which is the logical reverse of the other statement and therefore does the same