police investigation
Refers to an investigation conducted by the police, often used in news or legal contexts.
As the police investigation progressed, new evidence was found.
The police investigation into this case has been prolonged.
捜査 is a general term for investigation, while 警察捜査 specifies that it is conducted by the police.
刑事捜査 refers to criminal investigation, which may be conducted by police or other agencies; 警察捜査 emphasizes the police as the investigating body.
Compound of 警察 (police) and 捜査 (investigation).