While this most likely does not create a situation where the investigator needs to be removed from the case, depending on your facts, it could provide useful questions for a criminal defense attorney to use to impeach that investigator's testimony at trial...especially if there's some reason the investigator would be biased against the person being charged.
My responses to posts on AVVO are not legal advice, nor do they create an attorney-client relationship. In order to provide true (and reliable) legal advice, an attorney must be able to ask questions of the person seeking legal advice and to thus gather the appropriate information. In order for an attorney-client relationship to exist, you and I both have to agree the the terms of such an agreement.
If you look at any given situation you could find a conflict. In criminal matters there are plenty of checks and balances that should lead to a just result. A lawyer may be able to assist.
This doesn't create a specific conflict of interest so that every time there would have to be a different officer/detective assigned to investigate such issue however case by case this could be addressed and information presented in order to establish a bias or conflict so that is would have to be done differently.
I agree. The investigator does not have the same ethical requirements attorneys do. If there is an ethical issue adverse to a defendant, that is something you could certainly bring up in trial, or potentially go to the n estimators supervisor.