What is the similarities and differences between a private detective and a private eye?

Answer 1

A private investigator is an ordinary person who is hired by a private person to investigate matters that are mostly civil as opposed to criminal matters. These would include finding out if a spouse is having an affair, tracking down a missing person or locating missing assets. A private investigator is also called a "private detective" sometimes. A detective is a policeman who is hired by a government agency to investigate criminal matters as opposed to civil ones.

What about the investigators that work at the District Attorneys office who only handle criminal cases?

Answer 2

There are no differences between a private detective and a private eye.

These titles are all the same the only difference is the name itself.

Private Detective

Private Investigator

Private Inspector

Private Eye (slang)

Private Dick (slang)

shamus (nick name)

The titles Detective, Investigator and Inspector are determined by each states professional license board.