I really like this concept. I liked going through the transactions to see where they said money came from, and then checking the other people to see if there was a matching debit. I was disappointed when it was just one level. I was gearing up to spend a lot of time playing this. I'll definitely be back to play more when there are more levels.
I also would have liked to be able to mark the suspicious transactions, rather than just picking somebody and throwing them to the wolves. There are only three options, so it's pretty good odds when picking at random. I like the idea that you might have selected the correct person, but they get away with it because you couldn't prove it by showing the actual transaction.