Rule 1.9 addresses conflicts of interest primarily with which group?

Rule 1.9 of the ABA Model Rules of Professional Conduct specifically deals with conflicts of interest concerning former clients. This rule is designed to protect the interests of individuals who have previously engaged a lawyer's services. It emphasizes that lawyers are obligated to maintain the confidentiality of information related to the former client, as well as avoid representing new clients in matters that are substantially related to those they handled for the former client, if it could negatively impact the former client's interests.

This rule serves to uphold the principle of loyalty to former clients, ensuring that they are not disadvantaged due to the attorney's subsequent engagements. The concern is particularly significant since the attorney may possess sensitive information about the former client that could create an unfair competitive advantage if used in representing someone else.

In contrast, the other options address different facets of conflict of interest. Current clients fall under Rule 1.7, which regulates conflicts regarding present representations, while the dynamics between lawyers within the same firm are typically addressed under Rule 1.10. Matters regarding judges and court officials generally fall outside the scope of the rules directly related to clients, focusing instead on judicial conduct and ethics.