[JURIST] A US Navy document [PDF] obtained by the ACLU under the Freedom of Information Act and made public Tuesday along with other records details 10 new and "substantiated" incidents of Iraqi prisoner abuse by US Marines, including one where Marines fired a pistol in a mock execution of four young Iraqi looters and repeatedly shocked another Iraqi detainee with an electric device until he "danced". It similarly details 10 other incidents that Navy investigators described as "unsubstantiated." The incidents took place some seven weeks after the first photos of the Abu Ghraib prison abuses were made public. The Navy documents obtained by the ACLU also describe an "exploding" Iraq caseload for Navy criminal investigators and allegations of "peer pressure" within the Corps to "keep one's mouth shut" about witnessed abuses. Marine officials said that as results of the investigations of the various incidents 13 Marines were convicted in court-martials and sentenced to up to fifteen months in prison. In a press briefing this afternoon in Washington before the ACLU documents were posted, a Defense Department spokesman emphasized that "in many cases, we are holding people accountable prior to people even knowing that there was a case, and that's not anybody's fault. That's just the way the military justice system operates. It's quick." The ACLU has posted copies of the Navy documents online here, along with an accompanying press release. Its full collection of FOIA documents on US prisoner abuse is here. Reuters has more.