Handling click events to open and close menus depending on the click target
The switch statement isn't needed.

Just set a click function for each class.

$(document).ready(function ready () {    
    $('.expandDropDown').click( handleBreadCrumbDropDownClick );
    $('.headlineTitle').click( handleAccordionItemClick );
});

function handleBreadCrumbDropDownClick() {
    var target = $(this);
    var dropDownList = $('#' + target.attr('data-itemprop'));
    var offset = target.offset();
    if ( dropDownList.hasClass('BC-DropDown-Open') ) {
        dropDownList
          .hide()
          .toggleClass('BC-DropDown-Open');
    }  else {
        if ( $('.BC-DropDown-Open').length ) {
            toggleDropDown('.BC-DropDown-Open');
        }
        toggleDropDown(dropDownList, offset);
    }   
}