MEXICO CITY (AP) — Soldiers executed at least 12 and probably 15 people at a warehouse in southern Mexico last summer, the government Human Rights Commission said Tuesday in a sweeping indictment of attempts by the military and civilian prosecutors to cover up the crimes. Commission President Raul Plascencia called it "one of the most serious human rights violations that can be committed" and issued a formal recommendation demanding prosecutors investigate clumsy and sometimes thuggish attempts to cover up the executions of the suspected gang members. The human rights investigation turned up gruesome details, including that someone had twisted the head of one suspect until his neck broke, Plascencia said at a news conference. The report said prosecutors either tortured the three women who survived the killings to force them to concur with the army's version of events, or allowed unidentified people to torture the women with beatings, partial asphyxiation, sexual aggression and threats of rape if they dared speak out about what really happened. The commission said state prosecutors, who said in July that they had found no evidence of executions, drew up dubious autopsy reports and did not take adequate crime scene photographs.