What's wrong here? "Johnson said the teen told officers he lit the fire and was arrested."
A "that" is missing.
The "and was arrested" part is unclear.
A pronoun is unclear.
A punctuation mark is missing.
Two of the above
MY ORIGINAL ANSWER
So, I was going for answer number 2. Let's break it down.
1) A "that" is missing: Well, a "that" after "said" or "officers" is optional, not required.
2) The "and was arrested" part is unclear: Well, it definitely is! When you first read the sentence, it seems as if the teen admitted two things: he lit the fire; he was arrested. The "and was arrested" part doesn't work. You need to reword it: "Johnson said the teen was arrested after he told officers he lit the fire."
3) A pronoun is unclear: It's true that two men are in this sentence, but I don't think the "he" is unclear.
MY REVISED ANSWER
OK. I admit it. If you didn't know that Johnson was a police officer, I see how the pronoun could be vague. I should have clearly said that Johnson was a cop. Shame on me!!