Kilpatrick Stockton LLP, an Atlanta-based firm, confirmed in a statement that attorney Mark Levy had died.

"Mark Levy was well known and highly respected for his successful appearances before the Supreme Court of the United States," said Bill Dorris, the firm's co-managing partner.

Levy was a deputy assistant attorney general in the Department of Justice between 1993 and 1995 and served five years in the Solicitor General's office.

D.C. Police spokeswoman Helen Andrews said officers were called to an office building where the firm is located to investigate a shooting Thursday morning. Investigators believe it was a suicide.

Levy attended Yale University's law school with former President Bill Clinton and Secretary of State Hillary Clinton and more recently worked on fundraising for Hillary Clinton's presidential campaign, said Dennis Gingold, an attorney who was working with Levy on a case.

"I don't know anyone who isn't shocked by what just happened," Gingold said. "He was a good guy. He really was ... and professionally, he was first class."

During his career, Levy had argued 16 cases before the Supreme Court. At Kilpatrick Stockton, he served as counsel and chair of the firm's Supreme Court and appellate advocacy practice. Levy, who was married and has two children, lived in Bethesda, Md.