Police certificates are not required for Pakistanis. Read below
you are older than 16 years of age: Police certificates are not required from Pakistan. However, an original police certificate is required from any countries where you previously lived. For more information on obtaining these certificates, visit Reciprocity by Country
Source: https://travel.state.gov/content/travel/en/us-visas/Supplements/Supplements_by_Post/ISL-Islamabad.html#:~:text=If you are older than,certificates%2C visit Reciprocity by Country.