I agree, my intent was not to say that there are no standard at all, but rather that the constitutional phrasing leaves a lot latitude. For example congress co

I agree, my intent was not to say that there are no standard at all, but rather that the constitutional phrasing leaves a lot latitude. For example congress could legislate that some specific crimes should use "preponderance of evidence" rather than "resonable doubt" or even require that the defendants prove their own innocence beyond resonable doubt. In the case of civil forfeiture I suspect that the individual whose property was seized has a constitutional right to appeal in some way, but also the constitution has little to say about the rules of that appeal process.