MIAMI — A previously convicted Haitian drug trafficker who voluntarily flew to Miami to face new charges in the federal assassination case of Haiti president’s agreed Wednesday to be detained as he appears to be cooperating with U.S. investigators as they zero in on a network of foreign and South Florida suspects. Rodolphe Jaar, a former Drug Enforcement Administration informant, is accused of playing a central role in providing housing, weapons and other support to a group of Colombian commandos suspected of murdering Jovenel Moïse in his home outside Port-au-Prince in July. Jaar’s assistant ...