The commander of Colombia’s army resigned Tuesday after an investigation tied dozens of military personnel under his command to an intensifying scandal over the killing of civilians by the armed forces in what apparently were attempts to inflate the number of insurgents or criminal gang members killed in combat by security forces. The resignation of the commander, Gen. Mario Montoya, 59, an American-trained officer who won acclaim for battlefield achievements during his 39-year career, comes amid a broad shake-up in the Colombian military even as it celebrates a string of victories in recent months against leftist guerrillas. Full Story