A lawyer from China recently sent me this question:  

How does American justice system treat a Red Notice? Will the authorities arrest the person right away upon discovering the Notice?

Before addressing the question directly, it is also important to consider the purpose of the question, which is to determine what will happen to a client if they travel abroad and are found to be the subject of a Red Notice.  While detention based on the Red Notice is certainly a possibility, it also must be recognized that non-citizens entering foreign countries are subject to immigration laws as well as criminal and extradition laws.

When an INTERPOL member country decides, for whatever reason, not to engage in the detention and extradition proceedings that can accompany the apprehension of a Red Notice subject, that country may instead rely on its immigration laws to (often more simply and quickly) deal with the subject.

Immigration authorities may take action such as prohibiting entry into the country at the airport or seaport; denying travel authorization prior to travel; or initiating deportation proceedings for the subject.

On the other hand, the member country often does utilize its criminal justice system instead of its immigration system to handle the case of a wanted individual.  In the United States, a Red Notice does not act as an arrest warrant.  Rather, a domestic warrant must be created after the Office of International Affairs determines that the underlying charges justify extradition proceedings.  Only then is a prosecutor assigned to the case to obtain an arrest warrant. If the court enters an order of extraditability, the Department of State makes a final determination of whether to turn the individual over to the requesting country.

If a subject is considered by the U.S. government to be a flight risk, the government may seek the subject's provisional arrest prior to the issuance of the arrest warrant. Interestingly enough, the government's Criminal Resource Manual contains a recommendation that prosecutors NOT request provisional arrest of a subject when the subject is not a flight risk, but simultaneously states a policy that it will object to bond in extradition cases as a matter of course:

9-15.700

 Foreign Extradition Requests ...

  3.   The government opposes bond in extradition cases.

9-15.230

 Request for Provisional Arrest...

[A formal request for extradition] is favored [over a provisional arrest request] when the defendant is unlikely to flee because the time pressures generated by a request for provisional arrest often result in errors that can damage the case.

It is true that the latter provision addresses requests by the U.S. government to other countries; but it's still fun to note that the government will always oppose bond in extradition cases, even though it recognizes that certain extradition subjects are unlikely to flee.

A final note:  the common thread to the lawyer's question, regardless of how the Red Notice subject is treated, is the fact that the Red Notice exists.  If the Red Notice is challenged and removed from INTERPOL's databases, the Notice itself can no longer form the basis for immigration difficulties or extradition proceedings.