I get the feeling the government is accusing the seismologists not so much of failing to predict an earthquake, as of assuring people in the area that an earthquake would not take place or at least lulling them into a false sense of security.
A quick nitpick. It's a prosecutor that started all this fuss, thankfully prosecutors have nothing to do with government proper (although there are laws in the works to subjugate them to the Parliament's veto).
Anyway, this is right. The explanation for the charge is that the guys gave "a too generic, half-assed and ineffective evaluation given what the team was supposed to do and their duties of prevention and prevision of seismic risk".
Italian article with that
I'd like to point out that those weren't just "scientists", they were guys in a team whose work was quake risk assessment. Other random scientists did shout End Will Come!!! for that quake, but they weren't in charge of a damn thing so their opinion was worth shit.
However, I'm not sure of the details- what the scientists said and when they said it.
The paper they produced on March 31 2009 (earthquake happened April 6), containing their risk assessment analysis.
To make a long story short, after some half-assed speculations where they don't think anything will happen, they conclude by clearly stating that they have no fucking idea if there will be an earthquake or not, due to lack of data about so small quakes preceding a big one in the past and the fact that other times there were swarms of small quakes and still no Big One after them, the fact Radon measurements are pointless and that there are no other ways at their disposal.
They conclude that the only defense is making buildings able to resist quakes.
Then, various political talking heads took out-of-context quotes from the above to state that there won't be any quake, and that the experts said so. Those should be the ones spanked. Maybe this will redirect the prosecutor to them.
Then you have guys like Paolo Stefanelli, the president of the national council of engineers, that keep reminding every now and then that stuff built in the fifties and sixties is likely to be a piece of crap and someone should do a law to do regular checks on the status of all buildings. (so far they do checks only after the buildings are completed, and then none does serious checks on them other than giving a look around every now and then)
Can a prosecutor in Italy do something like that?
Sure they can, but they can be shot down. There is a check to see if there are good reasons to proceed. The session to decide if this is worth or not the fuss is scheduled for September 20 (as per the link above).
something with more of the color of state policy
A general rule of thumb for you. If it doesn't benefit Berlusconi, it isn't state policy.
As I said, the Judiciary is still remarkably uninfluenced by the other two powers (executive and legislative, both in the hands of Berlusconi).
There is a reason why they get routinely called "red (=communist) gowns" by him.
I have to fix a mistake I made above. Judge Giuseppe Romano is a "Gup", a judge that decides if the trial can start or not.