Here's the answer:
“경찰은 살인범을 현행범으로 잡았어요”
Watch a real native speaker say it:
Here's how it sounds in a textbook:
Fun fact: the hundreds of thousands of people learning Korean with Memrise get this phrase correct 96.6% of the time!
Fun fact: the hundreds of thousands of people learning Korean with Memrise get this phrase correct 96.6% of the time!