I have heard this statement used in the context of debate on gun ownership, can someone explain please?
It means that the murderer isn't the Gun, its the person.
Had they no gun, they'd run over you with a car, or chop your head off with an axe.
Think of it like this...
When Obama was still President, his last Executive order was to give Iran about half a billion dollars.
They took this money and gave it to Hamas and the Taliban, who then used it to buy weapons to kill innocent people.
So, who murdered the innocent people?
A.) Obama......as he financed their deaths.