Special Commission of Inquiry, established by the Betancur government, released a June 1986 report which concluded that Escobar had no relation with this event, so these allegations could not be proven (though it did not rule out the possibility either). Carrigan alleged that the act was a conspiracy of the Colombian government. Others state that the alleged Guerrilla-Cartel relation was unlikely to occur because the two organizations had several standoffs and confrontations, like the kidnapping of Nieves Ochoa, the sister of Medellin cartel founder Juan David Ochoa, by M-19. The kidnapping led to the creation of the MAS/Muerte a Secuestradores ("Death to Kidnappers") paramilitary group by the Medellin cartel. However, her theories and skepticism of Escobar and the Medellin Cartel's involvement was greatly discredited by others such as Rex Hudson, who presented allegedly "overwhelming evidence" linking the cartel to the plot. Former Assistant of the Colombia Attorney General, National Deputy Comptroller, author and Professor Jose Mauricio Gaona along with Former Minister of Justice and Ambassador to the United Kingdom Carlos Medellín Becerra, the sons of two of the murdered Supreme Court magistrates, have pushed for further investigations into the presumed links between the M-19 and the Medellín Cartel drug lords. Mayor of Bogota Gustavo Petro, a former M-19 guerrilla, has denied these accusations and dismissed them as based upon the inconsistent testimonies of drug lords. Petro says that the surviving members of the M-19 do admit to their share of responsibility for the tragic events of the siege, on behalf of the entire organization, but deny any links to the drug trade. Notable members Antonio Navarro Wolf Vera Grabe Carlos Toledo Plata Gustavo Petro Luis Otero Cifuentes Rosemberg Pabón Gustavo Arias Londoño Andrés Almarales Marcos Chalita Carlos Moreno Demobilization and participation in politics Internationally isolated, M-19 saw itself unable to continue the armed struggle: As late as 1988, an attempt was made to solicit weapons shipments from Socialist East Germany, but, following reservations from the Ministry of National Defense, the Foreign Ministry, and the Ministry for State Security, the request was denied in the end. The M-19 eventually gave up its weapons, received pardons and became a political party in the late 1980s, the M-19 Democratic Alliance ("Alianza Democrática M-19", or (AD/M-19)), which renounced the armed struggle. Eventually the M-19 returned Bolívar's sword as a symbol of its demobilization and desire to change society through its participation in legal politics.