coinvestigator
/ˌkoʊɪnˈvɛstɪɡeɪtər/
noun
- A person who works with one or more other people to investigate something, such as a crime, scientific research, or a problem.
- Each coinvestigator on the research project is responsible for a different part of the study.
- The lead detective and her coinvestigator interviewed the witnesses together.
- The two professors served as coinvestigators on the grant proposal.