The magazines may have been stolen from the military, or they may have been surplussed. At this point, we don't know. The fact that they had "restricted use only" stamped on them only means that they were made after the federal ban on them went into effect in 1994. That stamping is to distinguish them from the mags made before the ban went into effect. The older mags were "grandfathered" in and were still legal to possess under both Federal and New York law. [Not sure what the just passed New York law says about them.] Since the older mags have nothing stamped on them, the newer mags (which the military and police could still legally acquire) had to have something stamped on them to distinguish them from the older ones. Such mags could and have (I believe, I'll have to check to be absolutely sure) been surplussed.
After the Federal ban sunsetted, mags so stamped, if surplussed, would be legal to possess under Federal law, but not under New York law which had no sunset provision.
You said, "Those magazines he possessed may have been US Army property." I have no problem with that. You are right. They may indeed be US Army property. If I had to guess, I'd say they were. But I don't know that for a fact, and neither do you, unless you have information that was not in the article.
Mylife said, "And they may have been surplus. If he stole them from the military that is another kettle of fish." I have no problem with that either. They may have been surplussed, as I pointed out above. So far, we're all good.
Then you said, "Before jumping to conclusions, don't you believe it best to get all the facts?" Good advice. But how does it apply to mylife's comment? You said "may," and he said "may." If he is jumping to a conclusion by what he said, are you not doing th same?
Glad you agree. We already see that this incident isn't cops gone wild.