SAN DIEGO — Marines from Camp Pendleton wantonly killed unarmed Iraqi civilians, including women and children, and then tried to cover up the slayings in the insurgent stronghold of Haditha, military investigations have found. Officials who have seen the findings of the investigations said the filing of criminal charges, including some murder counts, was expected, which would make the Nov. 19 incident the most serious case of alleged U.S. war crimes in Iraq. An administrative inquiry overseen by Army Maj. Gen. Eldon Bargewell found that several infantry Marines fatally shot as many as 24 Iraqis and that other Marines either...