Scroll all the way down to the bottom of the document, find the M_Y_Cop lines and replace them with this:

M_Y_Cop,			M_Y_COP_BLACK,				0
M_Y_Cop,			M_Y_COP_HISPANIC,			1
M_Y_Cop,			M_Y_COP_BLACK,				2

What this does: Each line represents a head in the m_y_cop.wdd, with the numbers on the right corresponding to the heads (0 is the Black head, 1 is the Latino head, 2 is the White head), and the lines in the middle determine which voiceline set each head uses. By default, the White head uses M_Y_COP_WHITE lines, but my edit makes it use the Black cop lines instead- here's why.

-The White cop voicelines include the M_Y_STROOPER_WHITE set. This means that White LCPD officers will erreneously refer to themselves as State Troopers.
-The Black cop voicelines are strictly for LCPD officers, so replacing the White cop lines with them means you will no longer hear LCPD officers in GTA IV or EFLC call themselves State Troopers.
-The Black cop voicelines include dialogue meant for an Irish White cop, making them a good fit for the White heads.