Dismissed without prejudice?

A friend of mine recently just had a case dismissed 'without
prejudice' in which he is being accused of a breaking and entering; I know
definitively that he is innocent. The accusing officer did not show for the pre-trial hearing, I assume b/c of lack of evidence. The defense attorney
motioned for dismissal with prejudice, but the case was ruled dismissed without prejudice.

The defense lawyer told him not to worry that it won't be
brought up again. How long does the prosecution have to bring this
case back into court?--> What is the likelyhood of this happening?

Will the charges remain on my friends record even though he is innocent and has not been convicted of anything? He has a strong case for his defense but wants it all to be over with. His face has been plastered all over the news, he spent a night in jail and was beaten up, and now everyone thinks he is a theif.

He has no prior record (25 yrs old) What measures should he take?
Should he just sit back and pray that he doesn't have to incur additional legal
fees and go back to court. How can his name ever be cleared?!

They in theory could do so for years.

But as a practical matter if it is not done relatively soon, say within months, it is likely it will not be pursued.

My husband had a case dropped per the D.A.'s request, then a few months later, without any new evidence or a new crime they are deciding to prosecute, so my guess is they can do whatever in the world they feel like doing!