plural of patient under investigation

(public health)

plural of private investigator

An agent hired by a private party for the purpose of investigation or evidence gathering.

A form of journalism in which the reporter deeply investigates a single topic of interest, often involving crime or corruption.

plural of principal investigator

(sciences) lead researcher on a grant-funded project

A journalist investigating a single topic of interest, often involving crime or corruption.

In terms of, or by means of, investigation.