No mention that I can find of the attempted large purchase of fertilizer 4 days before the blast.
He apparently tried to buy Ammonium Nitrate at a place called Feed and Seed. The links have been posted on the main thread. You can also search for "Norman Bombing" as a key word and there is an entire article devoted to his failed attempt.
Don't know if this has been mentioned, but on Channel 6 this morning, apparently there was an off duty officer in the fertilizer store at the time of this purchase request who was concerned enough about it to get this guy's tag number.