The Supreme Judicial Court today upheld a Texas native's conviction for illegal possession of an assault weapon and illegal possession of another gun, ruling that the Second Amendment still gives Massachusetts the right to ban assault weapons and regulate ownership of other guns.

At issue were the "AK-47-style pistol," four 30-round magazines and a 9-mm pistol that had been modified to hold up to 20 rounds that John Cassidy brought up here with him in 2010 after he enrolled at the University of Massachusetts Law School in Dartmouth. Cassidy obtained copies of Massachusetts gun-registration forms but never filed them, saying the fees were too expensive for him. He also cited Texas law, which let him walk around with the weapons - something he legally might not have been able to do here with the AK-47 pistol, in any case, since it's classified as an "assault weapon" banned under Massachusetts state law.

Cassidy was arrested in March, 2011 on seven counts: Illegal possession of an assault weapon, illegal possession of a gun, illegal possession of four high-capacity feeding devices and illegal possession of ammunition, after Dartmouth police obtained a search warrant for the apartment he shared with another law student.

The defendant testified in his own defense. He said that the firearms were his, he had been hunting since he was eight years old, he purchased the firearms legally in Texas and brought them with him when he started law school, and he had not applied for a license or FID card after his arrival in Massachusetts.

Cassidy made several arguments for overturning his conviction: He said prosecutors failed to proved that he "knowingly possessed a large capacity firearm and large capacity feeding devices," that state gun laws are "unconstitutionally vague" because they are "too complex to be understood and are enforced arbitrarily," that the Second Amendment gives him the right to bear arms and that Massachusetts prosecutors and judges don't understand the Massachusetts constitution because the equivalent gun section of the state constitution should be interpreted to mean "individual" gun rights, not "collective" gun rights.

The state's highest court rejected all his arguments.

The jury concluded that Cassidy knew that both weapons could hold more than 10 rounds of ammunition - the Massachusetts definition of "high capacity" - and cited a 2000 gun ruling that essentially said ignorance was no defense.

Given the defendant's testimony about purchasing, loading, and shooting the two firearms; the manner in which he kept the AK-47-style pistol with its magazine unloaded; the manner in which he kept the nine millimeter pistol partially loaded (to save the spring from wear), but locked (for safety and accessibility); and the obvious large size of the thirty-round "banana-style" magazines and the after-market magazine, the jury reasonably could have inferred that the defendant was aware that the magazines held more than ten rounds of ammunition.

The court tied the ignorance issue into its discussion of whether our gun laws are too vague:

The statutes challenged by the defendant clearly indicate what is required of individuals who wish to possess firearms legally in the Commonwealth. The defendant testified that he was aware before his arrest that Massachusetts required registration of firearms, and that he had not registered either of his weapons because of the cost. In some circumstances, the Supreme Court has concluded that ignorance of the law may be a defense, where proscribed conduct is completely passive and a defendant has no reason to know of the requirements of the law. See Lambert v. California, 355 U.S. 225, 228-230 (1957) (holding that defendant could not be convicted of violating felon registration ordinance by virtue of her mere presence in city). Such a claim is unrelated to a facial vagueness challenge, and does not appropriately describe the defendant's conduct here. The defendant's vagueness claim therefore fails.

The right to bear arms? The court noted that even in the Heller decision, which outlawed a particularly strict gun-control law in Washington, DC, the Supreme Court held that the Second Amendment, like all other amendments, is not absolute and that states and localities were allowed to continue to regulate guns as long as they do not interfere with a person's right to self defense - and that there is no mistake in how Massachusetts courts have interpreted the section of the Massachusetts constitution that deals with the right to bear arms.