BOGOTA, Colombia -- Colombia's chief prosecutor stood between the white plastic-sheathed remains of two dismembered teenage sisters. On the rust-colored dirt around him lay remains of nearly 60 newly unearthed victims of paramilitary death squads.

Not just their killers but those who bankrolled them must be brought to justice, Mario Iguaran told reporters last week at the mass grave in the country's eastern plains.

He spoke ahead of a trip to Washington this week to seek aid for his overburdened office and help obtain evidence against U.S.-based multinationals he's investigating for allegedly financing the paramilitaries.

Iguaran meets with U.S. Attorney General Alberto Gonzales on Monday and Sen. Patrick Leahy of Vermont, chair of the Senate Judiciary Committee, on Tuesday. With both, he is sure to talk about Chiquita Brands and the Alabama-based coal company Drummond Co. Inc.