Hearing the kidnapper's words, everyone present furrowed their brows.
In typical kidnapping cases, there are several key 'points' that influence the development of subsequent events, the most important of which is the kidnapper's reaction upon learning that the victim has alerted the police.
Notifying the police brings significant psychological and mental pressure to the kidnapper. Despite having anticipated that the victim might call the police, the highly tense nature of kidnapping as a 'job' often leads to most kidnappers reacting furiously and injuring the victim. In the gravest of cases, they might even kill the victim outright.
Even if they don't harm the hostage immediately, alerting the police sends a signal to the kidnappers that their operation has entered a more challenging phase and must end quickly. The entire process becomes fraught with danger, and the slightest provocation might provoke the kidnappers into extreme actions.