I think it was asked what I make of the word "again". I think in context it could mean just walking again,
She said 'walking back again', not 'walking again, back'. Whatever she meant by 'back', it was also being repeated.
I think she meant 'back home', as in 'back home from the store', as opposed to 'out to the store'.
or it could mean headed to the 'T' again.
Dee Dee never said anything about the 'T', by any label or description. The only geographical locations she mentioned were 'his dad's house', the store, and the mail shelter. There was no apparent reason for Martin to be going back to the 7-11 or the mail shelter.
Dee Dee describes TM by his dad's house, then walking somewhere else while keeping his voice low.
Dee Dee didn't say he was walking somewhere else. That's your interpretation.
I think 'walking back again' most likely meant that Martin was walking on the route to 'his dad's house', as he had been before he briefly ran along the same route.
Dee Dee also didn't comment on the volume of Martin's voice during the 'couple of minutes' that he was presumably continuing to walk. His voice being low may have applied only to the moment that he told her he thought he had lost the man following him.