 Ferrer practiced law in Miami, focusing on civil litigation, including suits involving medical malpractice, wrongful deaths, personal injuries and commercial business litigation.In 1995, he became an associate administrative judge in the criminal division of the 11th judicial circuit, which covers Miami-Dade County, where he spent ten years presiding over criminal cases.He also served as an appellate judge over appeals from the Miami-Dade County Court, county commission and other agencies.