Sean McKessy, the former head of the U.S. Securities and Exchange Commission’s Office of the Whistleblower, has joined the whistleblower law firm Phillips & Cohen as a partner in its Washington office.

McKessy, who left his post as first chief of the SEC’s whistleblower office in July, “played a pivotal role in transforming the SEC’s culture into one that enthusiastically welcomes whistleblowers and appreciates their critical role in advancing the SEC’s enforcement agenda,” said Erika Kelton, a partner and whistleblower attorney at Phillips & Cohen, in a statement.