We don't know what convenience store he went to. If you click through the map at the top of the thread, the nearest 7-Eleven is marked on it. It is about a 20 minute walk from the home where Martin was staying.
There is just so much weird about this whole thing. TM actually went to the 7-11 in the rain for as brother Al said “IT and skillets”? The whole media hysteria thing always makes me think there is something big missing. Obviously it’s the truth that’s missing.