How does good faith defense work with a strict liability law?

Question

I was scanning Wikipedia's article on strict liability in the US and it has this quote:

However, in United States v. Kantor,[15] which concerned underage pornographic actress Traci Lords, the Ninth Circuit Court of Appeals introduced a "good faith" defense against crimes in which the victim intentionally tricked the defendants into a factual mistake thinking that no crime was being committed.[16] A "good faith" defense requires showing that the defendant affirmatively had reason to believe that they were not committing a crime, not simply a lack of knowledge that they were.

Could someone better elaborate on the distinction, what is the burden of proof for not having mens rea and what is the burden of proof for good faith, and how do the differ?

To give a specific example I know statutory rape laws are strict liability laws, The very same Wikipedia article on strict liability even says "it is possible to face felony charges despite not knowing the age of the other person, or even if the minor presented identification showing an age of eighteen or higher". However, if good faith arguments are allowed for strict liability laws then why would not someone looking over the age of consent and providing apparent proof of that fact not be sufficient for a good faith defense?

Answer 1

Affirmative defenses generally have a subjective or objective factual test for the jury to consider. In this case, the test may be something along the lines of "Given the totality of the circumstances, did the defendant take objectively reasonable precautions to make sure the victim was not underage, or would the defendant in particular have any additional reason to believe the victim was underage despite their precautions." So to answer the original question more specifically, a person could still be guilty of the rape even if the victim took steps to try to trick them if the jury is unconvinced that the defendant acted objectively or subjectively reasonably (depending on the local statutes). A prosecutor could show the jury the fake ID card, for example, and argue that it is obviously fake, or argue that there are other factors that should have led to the defendant knowing that the person was underage - for example, because the defendant has met the victim before and would have known their approximate age.

Answer 2

Could someone better elaborate on the distinction, what is the burden of proof for not having mens rea and what is the burden of proof for good faith, and how do the differ?

To give a specific example I know statutory rape laws are strict liability laws, The very same Wikipedia article on strict liability even says "it is possible to face felony charges despite not knowing the age of the other person, or even if the minor presented identification showing an age of eighteen or higher".

To start with the specific example, it is common for a jurisdiction to have a mix of: (1) mens rea requiring, and/or good faith affirmative defense available offenses (typically for non-commercial sex with someone of late middle school or high school age) and (2) other strict liability offenses for which there is no mens rea rquirement (although some voluntary act called an actus reus is required), and there is no good faith defense (typically for commercial sex with a minor, or with someone who is at an age that is typically prepubescent like 11 or 12 years old or younger).

If mens rea is required, the prosecution must prove its existence beyond a reasonable doubt in their case in chief.

If mens rea is not required but there is a good faith affirmative defense, then the prosecution doesn't have to prove this in their case in chief, but evidence or argument in support of the defense has to be offered by the defendants at trial and must meet the applicable standard of proof (sometimes once raised, the prosecution must disprove it beyond a reasonable doubt, sometimes the defendant must prove it by a preponderance of the evidence; jurisdictions vary on this fine point).