Robert Haar's practice involves primarily civil and criminal trials and appeals in both federal and state courts. His civil litigation practice has included representation of universities, law firms, banks, major corporations, insurance carriers and individuals in many contexts, including commercial, securities, professional liability, intellectual property, environmental and constitutional litigation. He has defended individuals and corporations in criminal proceedings and in conjunction with grand jury investigations. A former law clerk to then-Justice William H. Rehnquist of the U.S. Supreme Court, he has been retained specifically for appellate work before the U.S. Supreme Court and federal courts of appeals.