According to https://travel.state.gov/content/travel/en/us-visas/immigrate/the-immigrant-visa-process/step-5-collect-financial-evidence-and-other-supporting-documents/step-7-collect-civil-documents.html under the section for police certificates, you only need to submit police certificates from your current country of residence if you've lived there for more than 6 months (if different from you nationality) and other countries you lived in for more than 12 months however, if you were arrested in any of those countries, you will need to provide a police certificate irregardless of how long you were there