DrTodd
Michigan Moderator
Not that I know of, but is possible... maybe. The common statement to a jury, or in court cases, is that the judge acknowldges the law has changed, but at the time the person was arrested/cited, the law was in effect.
Here is a recent 2A case that SCOTUS declined to hear:
US v MASCIANDARO (2011)
Sean Masciandaro was convicted of carrying or possessing
a loaded handgun in a motor vehicle within a national park
area, in violation of 36 C.F.R. § 2.4(b). He challenges his conviction
on two grounds: (1) that he was improperly charged
under § 2.4(b), because after he was arrested but before he
was tried, that regulation was superseded by a more lenient
regulation that provided for state law to govern the legality of
his actions; or alternatively (2) that section 2.4(b) violates the
Second Amendment as applied to him and facially.
Because we conclude that the holding in United States v.
Hark, 320 U.S. 531 (1944), as well as the general federal savings
statute, 1 U.S.C. § 109, denies defendants an automatic
entitlement to the benefit of post-arrest changes in the law, we
find that Masciandaro was properly tried under the law as it
existed on the date of his arrest.
-http://www.ca4.uscourts.gov/Opinions/Published/094839.P.pdf
