 Journalists such as Harlan <unk> attributed the split to Means and other AIM members dividing over opposition to the Bellecourt brothers because of their alleged involvement in the execution of Anna Mae <unk> in December 1975 , who was then the highest @-@ ranking woman in AIM but had been suspected of being an informant . It was a year in which other FBI informants had been discovered in AIM . On November 3 , 1999 , Means held a press conference in Denver , Colorado in which he accused the Bellecourt brothers of complicity in <unk> 's death , and named three lower @-@ level AIM members involved in her death : Arlo Looking Cloud , John Graham , and Theda Nelson Clark . This was the first time that an AIM leader active at the time of the <unk> murder had publicly accused AIM of having been involved . 
