sentences:  On February 15, 2008, Rosenthal resigned as Harris County district attorney, following the filing of a lawsuit petitioning for his removal from office.The press release issued by Rosenthal suggests substance abuse played a part in his decision.Rosenthal's official release claims, "Although I have enjoyed excellent medical and pharmacological treatment, I have come to learn that the particular combination of drugs prescribed for me in the past has caused some impairment in my judgment."