FBI agents are mourning the death of one of the Bureau’s top financial crimes supervisors who reportedly shot and killed himself on a crowded nite-club dance floor, according to top FBI insiders. Salvatore “Sal” Cincinelli, a former Wall Street broker who joined the FBI in 2010, died last week during a night out after an FBI training session, sources said. Cincinelli was one a supervisory special agent who spearheaded many of the FBI’s high-profile and complex Wall Street investigations, including probing the finances of the Clinton Foundation. After leaving his Wall Street career, Cincinelli was first assigned to the New...