(Arlington, WA)  --  Investigators say two brothers who are accused of murdering an Arlington, Washington couple may be headed for Mexico.  John and Tony Reed are each wanted for first-degree murder in the presumed deaths of Patrick Shunn and Monique Patenaude.  Officials say the suspects are believed to be in a gold, 2002 Acura 32T with Arizona plate BNN-9968.  The bodies of Shunn and Patenaude haven't been found.