&gt; And if they find a gun on you[2] when they stop you for real cause, they shouldn&#x27;t need a warrant to seize that gun.<p>Yes they should.  Either they are arresting you and the gun gets processed like everything else, or they aren&#x27;t arresting you and thus need a warrant to seize anything from you.  If they don&#x27;t have enough evidence to arrest you for the crime then they don&#x27;t have enough evidence to seize the gun without a warrant.