Interesting items:
- This is from the NY State courts so it is NY State laws in play (likely campaign finance laws), not Federal. If it were Federal it would be prosecuted by Federal attorney's in a Federal court.
- A Grand Jury (for those that don't know) is composed of citizens, about 16-20 or something, that proceed like a court case understanding laws and evidence presented, including witness interviews, and the result here is that they chose to indict. This means that 12 (or more) citizens decided there was enough evidence that specific laws might have been broken to bring charges against him.
- I believe (common sense here) that campaign finance funds have to be kept separate from personal or business funds, as in different accounts. Depending on the laws in various states the laws may require disclosure forms of funds into/out of the accounts, etc.
Its likely that this is technical and could be traceable - if the funds for hush money came from a campaign finance account through his attorney and noted as such its probably not a case that is worth trying. That doesn't appear to be illegal, its a (morally questionable) campaign line item. If the source of the funds was from a personal/business account then that could violate campaign finance laws by using the wrong account. This kinda sounds like how they got Al Capone on tax evasion and not the myriad of other potential crimes. I'm not comparing the people, just my layman knowledge of the cases.