If one is stopped, and the officer starts asking questions which one does not wish to answer, does one have to invoke the right time after time after time; or can one simply invoke the right in general terms such as "I am invoking my fifth amendment right to remain silent; and I will, from this point, refuse to answer any further questions."?
Also, if one may invoke on the basis above, does that invocation become null and void if one does answer any question, or have any further communication after that invocation? Does one have to re-invoke the right in general terms -- assuming that is permissible -- once again?