[BMUK]

Skinid's are not floats.

This is all you need.

pawn Code:

new CopSkinsL1[] =
{
    280,
    281,
    282,
    283,
    265,
    266,
    267,
    288
};

pawn Code:

SetPlayerSkin(playerid,CopSkinsL1[random(sizeof(CopSkinsL1))];