investigation-n; 2 Senses

Sense Number 1: a legal inquiry into possible criminal activity

Commentary: INVESTIGATION[+inquiry][+legal][+criminality][+possible]
NOTE: often implies an inquiry into possible criminal behavior of an individual
NOTE: Sense 1 is a specialized, narrow sense of Sense 2
NOTE: implies a legal proceeding

He is under investigation for possible money laundering activities.
There is certain to be a full investigation by the FAA following this near mid-air collision.
There was never a police investigation of the curious events surrounding the man's death.

WordNet 3.0 Sense Numbers: 1

Sense Number 2: a general systematic study or exploration of a topic

Commentary: INVESTIGATION[+systematic][+exploration][+topic]
NOTE: does not imply inquiry into alleged criminal or negligent behavior
NOTE: implies a general intellectual pursuit of a topic.
NOTE: does -not- imply a legal proceeding

Her thesis topic is an investigation of possible effects of increased carbon dioxide in the ocean.
Wittgenstein's later work was an investigation of deep philosophical issues related to language
and logic.
My investigation of the backyard revealed that raccoons had been digging for grubs in the garden.

WordNet 3.0 Sense Numbers: 2