As I noted earlier, the federal magistrate suggested at the arraignment that the defense in the Portland bomb sting case might be able to move to suppress evidence as a result of possible entrapment. I'm paraphrasing a paraphrased report, so it's possible that the magistrate judge wasn't actually suggesting a suppression motion about the entrapment so much as outrageous government conduct. But in the event that it was about entrapment, I took a quick look at some cases, and I didn't see anything to indicate that entrapment can be litigated as a pre-trial matter through a motion to suppress.
If anything, the cases, admittedly from outside the Ninth Circuit, go the other way. In Fletcher v. U.S., 295 F.2d 179, 181 (D.C. Cir. 1961), the court held:
We think untenable the position that the trial court should have suppressed the evidence of violation of the narcotics laws seized under the arrest and search warrant because the warrant was based on actions allegedly constituting entrapment. Even if there had been entrapment- which we hold there was not- that position would extend the suppression of evidence doctrine to lengths beyond any which have been drawn to our attention.
In U.S. v. Mitchell, 493 F.2d 9, 10 (5th Cir. 1974) and Matherne v. U.S., 397 F.2d 406 (5th Cir. 1968), the courts reached similar conclusions. This isn't surprising, since Jacobson v. United States, 503 U.S. 540, 549 (1992), holds that entrapment must be decided by the factfinder under the usual "proof beyond a reasonable doubt" standard, and therefore, arguably not in a pre-trial motion.
However, there is a concept known as "sentencing entrapment," and even better, it is recognized in the Ninth Circuit:
Sentencing entrapment or sentence factor manipulation occurs when a defendant, although predisposed to commit a minor or lesser offense, is entrapped in committing a greater offense subject to greater punishment.
U.S. v. Staufer, 38 F.3d 1103, 1106 (9th Cir. 1994). A lot of these cases involve defendants who were convicted of drug offenses, for which the quantity of drugs determines in large part the sentence, and where they were pre-disposed to buying the drugs but were entrapped in buying even more. The proper remedy has been to sentence the defendant based on the quantity of drugs that did not involve entrapment.
This is a sentencing issue, which implies conviction, of course, so it's not something that I would expect to come up in a pre-trial setting. I'm not sure that this could be applied even if Mohamud were to convicted under the indictment -- it would appear to be an issue of first impression as to 18 USC 2332a, but perhaps it's a sentencing argument one could keep in a back pocket to be used if necessary.