Which of these entities is not involved in providing private investigation services?

The correct answer identifies a consumer reporting agency as an entity not involved in providing private investigation services. Consumer reporting agencies primarily focus on collecting, maintaining, and distributing consumer credit information and related data. They are mainly concerned with credit reporting and risk assessment for lending purposes, rather than conducting investigations in a manner typical of private investigators.

In contrast, a certified public insurance adjuster is involved in assessing and investigating insurance claims, which is a service related to private investigations. A registered professional engineer may perform investigations related to engineering or technical issues. A commissioned peace officer, even if not seeking compensation, might conduct investigations as part of their law enforcement duties. Hence, while the other options are related to investigative functions in some capacity, a consumer reporting agency does not engage in the same type of private investigative services.