It was not a fully automatic rifle, but a semi-automatic 5.56 rifle that had a .50 AE top end put on it (according to one news report - that could be bogus scoop also, however...).
According to news reports he had defaced the serial number of the rifle.
Sounds like a troubled dude.
Stories --
http://www.nj.com/news/index.ssf/201...an_had_we.html
http://www.jihadwatch.org/2010/01/gr...-headdres.html
http://www.kmtv.com/Global/story.asp...&nav=menu550_2