What conflicts arise when a public defender’s former client becomes a state witness against a current client?

Plain-English summary

A public defender’s former client, represented on unrelated charges, was endorsed as a state witness in the defender’s current client’s case.

The opinion identifies a Rule 4-1.9(b) conflict if information from the former representation, not generally known, could be used to the witness’s detriment. If effective current representation requires disclosure but not detrimental use, it identifies a Rule 4-1.7(b) conflict. Under either, the former client may waive; otherwise the defender’s office should withdraw. The defender must tell the current client about the earlier representation.

Currency note

This opinion was issued in 1996, before Missouri’s 2007 revisions to the Rules of Professional Conduct. Subsequent rule amendments or later opinions may have changed the analysis. Treat this page as historical context and verify current rules before relying on it.

Common questions

Q: When does Rule 4-1.9(b) apply in the answer?

A: When nonpublic information from the former matter could be used to the former client’s detriment.

Q: Whose waiver would avoid office withdrawal under the opinion?

A: The former client’s waiver.

Background and rules framework

The answer cites Rules 4-1.9(b) and 4-1.7(b) for distinct information-use and disclosure conflicts.

Citations and references

Missouri Rules of Professional Conduct:

• Rule 4-1.9(b)
• Rule 4-1.7(b)

See also

• Missouri Informal Op. 960263: Company Witness Information
• Missouri Informal Op. 960248: Former Client Adverse Witness

Source

• Landing page: https://mo-legal-ethics.org/informal-opinion/960170/
• Rule revision reference: Missouri Informal Opinion 970082

Original opinion text

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

QUESTION: Attorney is a public defender. Attorney previously represented Client 1 on charges unrelated to the charges on which Attorney is now representing Client 2. Client 1 has been endorsed as a witness for the state. (1) Does Attorney have a conflict and, if so, can it be waived by Client 1? (2) If Attorney has a conflict, must Attorney´s office withdraw from representation of Client 2? (3) Does Attorney have a duty to disclose the prior representation of Client 1? ANSWER: (1) If Attorney obtained information in the course of representing Client 1 that has not become generally known and that could be used to Client 1´s detriment in the representation of Client 2, Attorney has a conflict under Rule 4–1.9(b). If proper representation of Client 2 would not involve using confidential information to Client 1´s detriment, but it would involve disclosure of such information, Attorney has a conflict under Rule 4–1.7(b). Client 1 could waive the conflict under either situation. (2) Under either type of conflict, Attorney´s office should withdraw, unless Client 1 waives the conflict. (3) Attorney has a duty to disclose the prior representation of Client 1 to Client 2.