detective:
(plural: ‘detectives‘; pronunciation: the letter ‘c’ is said with a ‘k’ sound as in “king”)

Lynn-Marie Carty, private detective, St. Petersburg
a person whose job is to find out secretly the information about others that will lead to criminals being caught, and also to find out about the criminals from the clues found at a crime scene, clues such as finger prints, footprints, or other articles that may have been left by the culprit;
a police officer with the skill of finding out secret information about runaway criminals (fugitives) or wanted criminals;
an investigator,

Robert Goren, Police Detective, Crime Squad
To be a detective, an ordinary person must get permission from the police and must time to time renew the license.
When she got a strong suspicion that her husband is cheating on her, Rebecca hired a detective to find out whether she was right or wrong.
Most of the insurance companies are known to appoint efficient detectives to investigate insurance claims they suspect may be false.
Police detectives, who are also called ‘plain clothes men’, never wear uniforms because they make their investigation secretly, and if they wear any sort of uniform, the public and the criminals recognise them
and may not cooperate with them for fear of getting involved in a police case!

a private detective
