an open-and-shut case

an ˌopen-and-shut ˈcase

(of a legal case, crime, etc.) so clear or simple that it can be dealt with or solved very easily and quickly: It’s an open-and-shut case. His fingerprints were on the gun and he can’t prove where he was that night.
See also: case
References in periodicals archive ?
One would think this would be an open-and-shut case of proper gun use under Louisiana law, which allows deadly use of force in defense of others to "prevent a violent or forcible felony involving danger to life or great bodily harm," but several items are clouding the issue.
The justices, however, did not take to the idea that this was an open-and-shut case of a woman's right to control her body, and Phillips was grilled at length.
132-7 (a) (2) seemed to make this an open-and-shut case in the employers' favor.
Add to that the unknown factors, such as fickle juries, and it would seem prudent to guarantee the accused Unabomber is kept behind bars by accepting his guilty plea, even though the government appears to have an open-and-shut case.