Verification of legitimate access of documents, which is one aspect of the umbrella of problems in the Insider Threat category, is a challenging problem. This paper describes the research and prototyping of a system that takes an ontological approach, and is primarily targeted for use by the intelligence community. Our approach utilizes the notion of semantic associations and their discovery among a collection of heterogeneous documents. We highlight our contributions in (graphically) capturing the scope of the investigation assignment of an intelligence analyst by referring to classes and relationships of an ontology; in computing a measure of the relevance of documents accessed by an analyst with respect to his/her assignment; and by describing the components of our system that have provided early yet promising results, and which will be further evaluated more extensively based on domain experts and sponsor inputs.