
Quoting
Taxing Matters
That scope can be enlarged, however, if during the Terry stop he discovers evidence of other potential offenses. As for the pat down for weapons or other dangerous items the officer is supposed to have some indication the person may indeed have something dangerous before conducting that search. Thus it is not automatic that a pat down search is justified in every Terry stop (though some cops seem not to understand that particular point). The courts look at all the circumstances of the stop to determine if the search was valid.