Voice of a Murderer (movie, 2007)

One day, the only son of famous news anchor HAN Kyung-bae, disappears without a trace. Soon, the kidnapper calls the mother demanding a $100,000 ransom. The police assign a veteran inspector to the case and assemble a top-notch task force to work under his command. But the kidnapper constantly outwits the police and continues calling the parents with yet more instructions for the money drop.