How to Change row colors based on the count

Hi All,

I developed a report using report builder. The columns are LAST_NAME, FIRST_NAME, EMPID, CASEID. I want to highlight those rows where there are more than one caseid. In the back end query i did a COUNT and ROW_NUMBER, but i do not want to include either the count or row number in the report, in short i want to highlight where there are more than 1 caseid per person. In the below case i want to highlight both the rows of SEAN SMITH. Greatly appreciate your suggestions .

Thanks

SV