Learn Turkish: Şu genç kadın polis mi? - Is that young woman a police officer?

The yes/no question particle follows 4-way vowel harmony. You look at the last vowel of the word right before it. The last vowel in polis is i, so the matching question particle is mi.

Where is the "is" in this sentence? Why doesn't mi have a personal suffix attached?

The "is" is naturally understood! In Turkish, the third-person singular ("he", "she", or "it") doesn't take a personal suffix. If you were asking "Are you a police officer?", you would add the "you" suffix to the question particle (polis misin?). But because we are asking about "that young woman" (she), it is just polis mi?.

Why use şu for "that" instead of o?

Both o and şu can mean "that". However, şu is used when you are actively pointing someone or something out to the listener, or if they are in your immediate line of sight. By saying Şu genç kadın, the speaker is likely directing the listener's eyes right to her.

The translation says "a police officer", but there is no bir (a/an) in the Turkish sentence. Why?