There’s no question that this guy was whacked both literally and figuratively. He was not found to be in possession of any significantly dangerous radioactive materials. The information suggests that he was interested in them with intent to produce a “dirty bomb”, but the article implies that he had a dangerous “cache of radioactive materials”.

Of the materials listed, only Thorium would fit that bill. It is weakly radioactive and emits alpha rays which aren’t harmful unless ingested or inhaled. Typically, Thorium is used in mantles of portable gas lanterns (remember using them as a source of alpha rays in science class?) or to produce certain alloys. A greater risk with Thorium is its flammability, especially when combined with the Lithium and Aluminum powder. I highly doubt that he had any significant quantities of Thorium.