Which matters could a former assistant defender prosecute after joining the prosecutor's office?

Plain-English summary

A lawyer moved from assistant public defender to assistant prosecutor and asked about cases pending at the defender's office during the prior employment and unrelated cases against people the lawyer had represented.

Under Rule 4-1.11, the opinion barred prosecution of a former-office case if the lawyer personally and substantially participated in it; being privy to confidential information counted as such participation. Under Rule 4-1.9(b), it barred prosecution of a former client if information from the earlier representation could be used to that person's disadvantage.

Currency note

This 1995 opinion predates Missouri's 2007 amendments to its Rules of Professional Conduct. An official reference note identifies July 1, 2007 amendments to Rules 4-1.9 and 4-1.10. 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: Did every case pending at the defender's office become off limits?

A: The opinion barred a case if the lawyer personally and substantially participated in it.

Q: What counted as substantial participation?

A: Being privy to confidential information about the case, according to the opinion.

Q: Could the lawyer prosecute a former client in an unrelated case?

A: Not if information from the prior representation could disadvantage the former client.

Background and rules framework

The opinion applied Missouri Rule 4-1.11 to prior public-defender-office matters and Rule 4-1.9(b) to prosecution of personally represented former clients.

Citations and references

Rules of Professional Conduct:

• Missouri Rule 4-1.11
• Missouri Rule 4-1.9(b)

See also

• Missouri Informal Op. 950129: Former prosecutor screen
• Missouri Informal Op. 950055: Former prosecutor's filed charge

Source

• Landing page: https://mo-legal-ethics.org/informal-opinion/950004/

Original opinion text

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

QUESTION: Attorney was an assistant public defender and is now an assistant prosecuting attorney. (1) May Attorney prosecute in cases which were pending in the public defender´s office while Attorney was employed there? (2) May attorney prosecute former clients who Attorney personally represented on unrelated matters? ANSWER: (1) Under Rule 4–1.11, Attorney may not prosecute in these cases if Attorney personally and substantially participated in the case while Attorney was in the public defender´s office. Attorney would be considered to have personally and substantially participated if you were privy to confidential information regarding the case. (2) This question is governed by Rule 4–1.9(b). Attorney may not prosecute if Attorney obtained information in the course of previous representation of the defendant that could be used to the defendant´s disadvantage in the current matter.