YOU SAID:
He ran away when he saw a police officer.
INTO JAPANESE
彼は警察官を見ると逃げた。
BACK INTO ENGLISH
He ran away when he saw the police officer.
INTO JAPANESE
彼は警察官を見ると逃げた。
BACK INTO ENGLISH
He ran away when he saw the police officer.
That didn't even make that much sense in English.