Can I use the phrase, “open and shut” for other subjects than legal cases?

Question

There was the following passage in New York Times (April 28) under the title, “In Baltimore, we’re all Freddie Gray.”:

“We’ve watched as Mayor Stephanie Rawlings-Blake, in conjunction with Police Commissioner Anthony W. Batts, spent over a week investigating what appears to be an open-and-shut case. I’d like to think that if I broke a person’s neck for no reason, I’d be charged in minutes. But the system — even when it’s run by a black mayor and a majority of the City Council is black — protects the police, no matter how blatant and brutal they are.

As I am unfamiliar with the expression,“open and shut,” I searched the meaning on Google, and found the following definition by the Free Dictionary among several sources:

Open and shut - If a legal case or problem is open and shut, the facts are very clear and it is easy to make a decision or find a solution

Is the usage of idiom, “open and shut” limited to legal matters? If it came from the instantaneous action of opening and shutting something like a box or drawer, why can’t we use it on anything, questions (e.g. simple calculation) or problems that are manifest or easy to solve other than legal cases?

Answer 1

An expression generally , but not exclusively, used referring to legal matters :

Open-and-shut case:

a legal case or other matter that is easy to decide or solve. (Oxford Learner's)

Open-and-shut case

a simple and straightforward situation without complications. (Often said of criminal cases where the evidence is convincing.)

• The murder trial was an open-and-shut case. The defendant was caught with the murder weapon. Bob's death was an open-and-shut case of suicide. He left a suicide note.

The Free Dictionary

• Chevrolet presents an open-and-shut case against the van you are using. ( From LIFE 12 giu 1970)

• An open and shut case?: Title of an article with political content.

• An Open-and-Shut Case? Recent Insights into the Activation of EGF/ErbB Receptors . A scientific/medical extract.

Answer 2

• Can I use the phrase, “open and shut” for other subject than legal cases?

Sure you can:

Origami Extravaganza! Folding Paper, a Book, and a Box ... - Page 27 Tuttle Publishing - 2000

Slide your index finger into K, and your thumb into I. Move your fingers in an open and shut motion to define the Fox's mouth (FIG. 12).

:-)