As you probably know already, Louisiana has a long (and on might say troubling) history as it relates to the duty of disclosing exculpatory evidence (see here and here), most notably Connick v. Thompson and Smith v. Cain (See here, here, and here).
Now comes word that the Louisiana Supreme Court has held that the duty to disclose exculpatory evidence in Rule 3.8(d) is not broader than the duty recognized by the US Supreme Court decision in Brady v. Maryland.
Although the ABA Standing Committee on Professional Responsibility has held that the Model Rule imposes a broader duty (see Formal Opinion 09-454), a few jurisdictions have held
otherwise. I have written about this in the past here.
Courts or Ethics Committees have also decided the duty under rules of professional conduct is broader in, at least, Washington, Utah, Texas, North Dakota, Massachusetts and the District of Columbia. The New York City bar's ethics committee has also issued
an opinion holding that a prosecutor's ethical obligation to disclose
exculpatory evidence is broader than the constitutional minimums
imposed by Brady v. Maryland. See N.Y.C. Bar Ass'n Comm. on Prof'l Ethics, Op. 2016-3, 7/22/15. Courts or Committees have decided otherwise in Ohio, Oklahoma, Colorado, and Wisconsin.
The Legal Profession Blog has a discussion on the new decision by the Louisiana Supreme Court here. The case is called In re Seastrunk and you can read the opinion here.