The New York Attorney General has filed a civil "complaint" against Donald Trump as well as some family members and companies. The allegations are centering around fraud by inflating property values in financial statements provided to banks and insurances.
As a German, I am confused: Civil lawsuits here do not involve the Attorney General (the Staatsanwalt) because they are disputes between private parties, usually arising from violated contractual obligations or damages. In such suits, the state is neither plaintiff nor defendant. In Trump's case, the banks or insurance companies would be the plaintiffs (but they didn't sue).
In criminal suits, by contrast, the Staatsanwalt takes on the role of plaintiff because somebody did an act that is deemed unacceptable. It is often the case but systematically not necessary that there is a damaged party.
Of course, some actions like fraud are criminal offenses — and are as such prosecuted by the Staatsanwalt — while also causing damage to third parties who can file a civil suit. But there would be two trials with totally different goals: One to prosecute a criminal act, and one to seek compensation for damage. (In reality, I think, the civil suit can be factually connected to the criminal suit because if the criminal suit asserts, say, a criminal fraud, then the damaged party has a better chance to make their civil case.)
In New York (and presumably other states) there exists, apparently, a hybrid type of suit: A civil suit where the plaintiff nonetheless is the state.
Still, this begs the question:
Why is this not a criminal suit? After all, the Attorney General is alleging fraud which, I must assume, is a criminal act even in New York.