on the case
01
used to refer to a situation in which one is taking legal action to solve a problem or crime
例
Officers on the case are unable to find a motive.
02
used when a specific task or a particular situation is being dealt with
Idiom例
Management is on the case now, and it looks as if things will return to normal soon.
Do n't worry; our best IT specialist is on the case to resolve the technical issue.
