Did a new partner’s prior firm being opposing counsel automatically disqualify the hiring firm?

Plain-English summary

A firm hired a partner from an opposing firm in a pending modification case. The partner had not appeared in the case and, according to the question, had no knowledge of it.

The opinion found no apparent conflict under Rules 4-1.9 and 4-1.10 on the explicit understanding that the partner had received no confidential information about the matter, whether in firm meetings or informal conversations.

Currency note

This opinion was issued in 1998, before Missouri’s 2007 revisions to the Rules of Professional Conduct. Later amendments or opinions may have changed the analysis. Treat this page as historical context and verify current rules before relying on it. The official Rule 4-1.9 and 4-1.10 reference notes identify July 1, 2007 amendments.

Common questions

Q: Did prior employment alone establish a conflict?

A: No, not on the stated facts.

Q: What knowledge would undermine the answer?

A: Confidential matter information gained at the old firm, including informally.

Background and rules framework

The answer expressly cited Rules 4-1.9 and 4-1.10 and limited its conclusion to absence of confidential information.

Citations and references

Missouri Rules of Professional Conduct:

• Rule 4-1.9
• Rule 4-1.10

See also

• Missouri Informal Op. 980163: Departing Associate

Source

• Landing page: https://mo-legal-ethics.org/informal-opinion/980109/

• Rule revision reference: Missouri Informal Opinion 20030007

Original opinion text

Reproduced from the official source for research purposes. The linked source is authoritative.

QUESTION: Attorney’s firm has taken on a new partner, who was formerly with another local firm. Attorney’s firm recently became aware that the new partner’s previous firm is on the opposing side in a modification case. The new partner was not the attorney of record and has no knowledge of the particular case in question. The opposing firm is now raising conflict of interest. Does Attorney’s firm have to remove themselves from the case?
ANSWER: Based solely on the information Attorney has provided, it does not appear that this situation involves a conflict of interest under Rules 4–1.9 and 4–1.10. This opinion is based on the understanding that Attorney’s new partner did not obtain any confidential information related to this matter while the new partner was at the former firm. This would include information obtained at firm meetings and through informal conversation.