Officer Massey joined the show in season three as a member of the Major Crimes Unit under Lieutenant Cedric Daniels. Massey is a world-weary officer with a penchant for sarcasm and cutting coupons.
She was particularly adept at deciphering the slang used by Barksdale drug dealers on wiretaps of cellular phones. Her diligent work manning wiretaps earned the respect of Lester Freamon when she was part of his successful undercover operation to supply pre-wiretapped phones to the Barksdale Organization.
In season four, Massey continued to work with the Major Crimes Unit and settled into her role. When the unit was assigned Lieutenant Marimow as a commander, Freamon transferred out. Massey and Sydnor were left to face Marimow closing down their wiretaps and ordering raids on weeks old targets.