Well, it looks like three people in Denver were arrested for giving false statements in what is being called a terrorism investigation. (Source.)
False Statements is one of those federal criminal laws that gets used a lot, and it’s fairly simple: under 18 U.S.C. § 1001, it is a crime for a person to knowingly and willfully make any materially false, fictitious or fraudulent statement or representation during a matter which is under the purview of the executive, judicial, or legislative branches. (There are a few other components to section 1001, but this is the part that trips most people up.)
Now, “materially” means that it has the tendency to influence the course of the investigation, and it’s really, really, really important to note that the threshold is pretty steep. There’s not even an “exculpatory no” doctrine to account for nervousness.
So, we’ll see what happens with this case.