My son was kidnapped and asked me for 5 thousand yuan. Is it useful to call the police? Will the police care?

According to the analysis of specific cases, you don't think kidnapping is a crime of kidnapping, but you must meet the constitutive requirements of kidnapping. What you said is too general. You can go to the local criminal police team and talk to the police about the specific situation. Those under the jurisdiction of the public security organs will accept it, but they will not tell you which part to go to. Kidnapping is a serious criminal offence. According to Article 239 of the Criminal Law, whoever kidnaps another person for the purpose of extorting property, or kidnaps another person as a hostage, shall be sentenced to fixed-term imprisonment of not less than 10 years or life imprisonment, and shall also be fined or confiscated. If the circumstances are relatively minor, he shall be sentenced to fixed-term imprisonment of not less than five years but not more than ten years and shall also be fined.

It seems to me that you are not in a hurry. You are still asking, is it a family conflict or a debt dispute?