In one of the most depraved cases of corruption in the Colombian armed forces in recent years, a Colombian court Monday convicted an army colonel and 14 soldiers of massacring 10 members of an elite, US-trained anti-drug police unit and an informant at the behest of drug traffickers. A judge in Cali found Col. Bayron Carvajal and his soldiers guilty of aggravated homicide for the May 2006 ambush outside a rural nursing home near Cali. The men will be sentenced in two weeks.

The soldiers bushwhacked the police unit as it was about to seize 220 pounds of cocaine that the informant had told them was stashed inside a psychiatric facility in the town of Jamundí. The soldiers fired hundreds of rounds at the police and attacked them with hand grenades. Six of the police officers were found to have been shot at close range. No drugs were recovered.

During the trial, more than a hundred witnesses testified. Some of them linked Carvajal to both leftist guerrillas and drug traffickers. Carvajal claimed his troops were attacking leftist rebels working with drug traffickers, but that didn't fly. Neither did the military's original explanation that the deaths were accidental. The military later conceded that its inquiries suggested links between the soldiers and drug gangs operating in the region.

Under Plan Colombia, the US has sent an average of $650 million a year in recent years to fight the drug trade and the leftist guerrillas of the FARC. Most of that money has gone to expand, equip, and train the Colombian military and police. Part of the rationale for that aid was that it would reduce corruption and human rights abuses in the Colombian armed forces.

The Carvajal case is not the only one to tarnish the image of the Colombian military lately. In the last two years, high-ranking military officers have been accused of selling secrets to drug traffickers to help them escape capture and planting fake bombs to advance their careers. Killings of noncombatants by the military are also reportedly on the increase after decreasing during the early years of Plan Colombia.

Meanwhile, for all the billions spent, that Colombian cocaine just keeps on coming.