There have been several investigative efforts to uncover what happened. An early investigation - dubbed "the historic truth" - under Mexican Attorney General Jess Murillo Karam of the government of President Enrique Pea Nieto, concluded corrupt municipal police from Iguala and neighboring towns, following orders from the local mayor, had turned 43 of the students over to the local drug cartel, Guerreros Unidos ("United Warriors"), who killed the students and destroyed their remains, and that Federal police and military played no part in the killings. This was disputed by some experts, such as the Inter-American Commission on Human Rights (IACHR), who found the findings "scientifically impossible". Another investigation (by journalist Anabel Hernndez) alleged that the commandeered buses were transporting heroin, without the students' knowledge, and the Mexican Army intercepted the drugs on behalf of the traffickers - the students being killed to eliminate witnesses.[7][8][9] There are also reports of military personnel monitoring the students' situation but refraining from helping them.[10][9]