Is a background check required for private firearm sales in Hawaii?

In Hawaii, a background check is required for all firearm sales, including private sales. This ensures that individuals who are prohibited from owning firearms, such as felons or individuals with certain mental health issues, are not able to purchase a firearm through private sales. Therefore, the correct answer is "Yes, always."

Options B, C, and D are incorrect because in Hawaii, background checks are required for all firearm sales, not just for certain types of firearms or under specific circumstances.