A month-long investigation by the Knox Police Department culminated in the arrest of two residents on meth charges last night. Alfred Higdon, 40, and Shari Melton, 39, were arrested at a home in the 300 block of Delaware Street. Officers reportedly found chemicals used in the manufacture of meth as well as methamphetamine and marijuana at the residence. Higdon and Melton both face charges of possession of methamphetamine, possession of precursors and possession of marijuana. Formal charges are pending.