How do they're become lunatics ? do they're find a secret chapter of the bible/koran and suddenly decide to go out and smite the unbelievers with lunatic attacks.Lunatics? Who are you trying to kid?
Has it not alluded to you that they tend to be all from a particular religion?
These individuals are not 'Lunatics' - stop giving them a free pass and associating them with people with real mental health issues.
Replace the words Loon / Lunatics with the word Muslims in your post, and it will make far more sense.
The victims in these attacks are victims of Islam, not victims of Mental Health.
If you dig in to the biographies of the lunatics, how they're became lunatic is ostensibly what prevent is supposed to stop. Of course, if the cause of lunacy is drugs/drink as in most cases, or someone like Bin Laden who fought on the fringes of a bloody insurgency against the soviets and likely as not had severe mental trauma(he came from a very wealthy background and wasn't up to the shock of war) then prevent is entirely useless.
A recognition that drugs can create lunatics and should be the first indicator to prevent would be a good empirical start.