I’m sure that some of you legal experts can chime in here. My guess is that the law says that to violate it, you must knowingly violate it, or something like that. But in most of criminal activity, I was under the impression that ignorance of the law wasn’t a defense. It has never worked for me when I’ve gotten a ticket for speeding. 
So what’s the straight dope as it relates to Edwards alleged* crime?
some crimes are specifically defined in the statute to require that the acts be done “wilfully” or “knowingly.” This type of wording is often used for more technical, regulatory type crimes, to ensure that the offence is only committed by truly intentional conduct. “Ignorance is not a defence” is a good general statement, but as laws get more and more technical (especially things like election expense law) you want to have a clear dividing line between accidental / negligent misuse of funds (which may attract civil liability) and a criminal act that attracts potential jail time. Also, considering the size and complexity of modern political campaigns, you don’t want the candidate to be criminally liable for mistakes made by every worker in the organisation, unless you can show that the candidate actually knew about it.
What Northern Piper said.
It’s true that there’s a general proposition, repeated endlessly: ignorance of the law is no excuse!
But that derives from the idea that all men know the law.
But really, that’s not always a safe or fair assumption. We can assume that all men know the laws that reflect what we call “malo in se” acts – actions that are wrong in and of themselves. In this thinking, we have a law against robbery, yes, but we don’t need a law to know that robbery is wrong. So it’s of no avail to claim that, as Steve Martin once based a comedy routine on, you forgot armed robbery was illegal.
Other acts are “malum prohibitum” – wrong because they are prohibited. Is counting depreciation as an allowable expense when figuring taxable income wrong? It might be, it might not be – we can’t rely on your innate sense of right and wrong to tell you, though.
So as a very general rule, offenses that require you knowing that the conduct was illegal – which really means that you knew or should have known – are applied to laws that are not necessarily well-known to all.
I’ve been led to believe that US federal tax law is one big fat exception to the “ignorance of the law is no excuse” principle for criminal violations.
Be careful, though. I don’t know anything about this case, but I’m fairly sure that for at least some statutes ‘knowingly’ applies to whether the person meant to do the action, and has nothing to do with whether the person thought it was illegal.
In other words, suppose a regulation requires a certain business to annually send in a signed 2236/B form, and this definition of knowingly is in the statute. If someone, through a clerical mix-up, sent in an otherwise correct but unsigned 2236/B form, and can show it was a clerical mix-up, then they’re off the hook, because they didn’t know that they failed to send in a signed form – they intended to, and thought they did, the action.
But on the other hand, if someone just didn’t bother finding out about the regulation, didn’t send in a from, and said “Hey, I didn’t know I was supposed to!”, tough titties for them; they’re still in violation.
And this makes sense – we don’t want to reward people for intentionally not finding out what they’re obligations are, but we don’t want to punish people who honestly weren’t aware of something like a missed signature.
Or, as explained in the great legal biopic Legally Blonde.
I don’t know if he’s being charged with “conspiracy” but I trust that knowledge has a great deal to do with proving guilt in those kinds of cases.
Yes, that’s my understanding as well, but it can get quite complicated on the facts of the particular case and the wording of the particular statute.
Here in Canada, our Supreme Court has made it clear that you don’t have to know that the act was criminal; you have to have intended the act. But that concept provides some grey area in a particular case.