it was easy. there are standard categories used for descriptive purposes. black male. white female. latino female. asian male. once race is KNOWN that is.
when people call the cops, they do the best they can to describe features. a victim may say "some arab looking dude stole my purse!"
we would then ask "how do you know he's arab?" and then we go on to ask about specific FEATURES -- hair color, eye color, skin color and tone, height, weight and a host of others. the "arab dude" may turn out to be a latino dude or a biracial dude or a white dude with a suntan.
i would use those descriptive terms, because that's the info that's needed.
who is going to catch the criminal first? the officer who says to be on the lookout for "some arab dude in a blue jacket and jeans" or the officer who says "a possibly middle-eastern male, short dark brown hair, blue eyes, approximately 6'1 and 190 lbs. last seen wearing navy blue jacket and blue jeans" ???
cops know that this description does not necessarily mean that the suspect IS of middle-eastern extraction. he could be latino, asian, white with a tan and dark hair, biracial, etc. a cop looking for a suspect described TO US as "mid-eastern" does not go around looking and think, "hmmm... well, that guy over there matches the description, but he's speaking spanish on the pay phone, so that surely CAN'T be the one!"
we go on features, plain and simple. race and ethnicity is just one, and we realize that those are GUESSES at best.
i've certainly never heard a cop on the radio say, "the suspect is an illegal mexican, and if he isn't illegal, well, he's certainly an immigrant!"
first off, we don't have those kind of mind reading powers. :)
secondly, guessing at race and ethnicity doesn't help us find the suspect.
or, a more familiar term might be, "just the facts, ma'am."
we go on facts, not guesses.