toriしら調shiraべるberuとりしら取調torishiraべるberu
1.

To conduct a thorough inquiry into a situation or subject, often involving close examination and detailed analysis of various aspects.

2.

To question a suspect or accused individual extensively in order to clarify the facts related to a possible crime or offense.

Example:

事件の原因を取り調べるために実情調査委員会が作られた。