Didn't remind guests to stay in the hotel to guard against fraud? Is the hotel responsible for the guest being tricked into calling the police?

No. The responsibility of a hotel is to provide safety and service, and provide a comfortable accommodation environment for its guests, not to control their behavior. If a guest is cheated for personal reasons or other external factors, the hotel usually does not bear direct legal responsibility, even if it calls the police, the hotel will not bear responsibility.