try this:
addEventHandler("onResourceStart",resourceRoot,function()
if source~=resource then return end
local policeTeam = createTeam ( "Police", 0, 0, 255 )
setTeamFriendlyFire ( policeTeam, false )
local players = getPlayersInTeam ( getTeamFromName ( "Police" ) )
if #players == 0 then return end --ends the script if there's no players on the police team
for _, player in ipairs ( players ) do
createBlipAttachedTo ( player , 0 , 2 , 0 , 0 , 255 , 255 )
end
end)