There is nothing particularly novel about the relation between atrocious human rights violations and US aid. On the contrary, it is a rather consistent correlation.
*The leading US academic specialist on human rights in Latin America, Lars Schoultz, found in a 1981 study that US aid "has tended to flow disproportionately to Latin American governments which torture their citizens,... to the hemisphere's relatively egregious violators of fundamental human rights." That includes military aid, is independent of need, and runs through the Carter period.
*In another academic study, Latin Americanist Martha Huggins reviewed data for Latin America suggesting that “the more foreign police aid given [by the US], the more brutal and less democratic the police institutions and their governments become.”
*Economist Edward Herman found the same correlation between US military aid and state terror worldwide, but also carried out another study that gave a plausible explanation. US aid, he found, correlated closely with improvement in the climate for business operations, as one would expect. And in US dependencies it turns out with fair regularity, and for understandable reasons, that the climate for profitable investment and other business operations is improved by killing union activists, torture and murder of peasants, assassination of priests and human rights activists, and so on. There is, then, a secondary correlation between US aid and egregious human rights violations.
 Lars Schoultz, “U.S. Foreign Policy and Human Rights Violations in Latin America: A Comparative Analysis of Foreign Aid Distributions” Volume 13, Number 2, January 1981 ( 2 of the graphs from the study are below)
Also from: Better lead than bread? A critical analysis of the U.S.'s Plan Colombia http://www.aqnt98.dsl.pipex.com/colombia.htm, which states the same Schoultz article can be found in: Stanford Central America Action Network (ed.), Revolution in Central America, (Colorado: Westview Press, 1983) pp 271 - 279.
Martha Knisely Huggins, Political Policing: The United States and Latin America, Duke University Press (July 1998) ISBN: 0822321726 p. 6 "Clearly, this review of some past and present recipients of U.S. police assistance calls into question U.S. public foreign policy documents, official government memoranda, and other discouse that has proposed that training foreign police owuld make these police more neutrally professional, positively humanitarian, and democratically responsive to civilian control. The date to be presented here suggest the contrary--that the more foreign police aid given, the more brutal and less democratic the police institutions and their governments become."
Noam Chomsky, Edward S. Herman, After the Cataclysm : The Political Economy of Human Rights: Volume II, South End Press, October 1979, ISBN: 0896081001
"These facts might lead a superficial observer to conclude that the U.S. government just likes torture. But causal connection can't be deduced from a correlation; we have to look further. This was done in a broader study carried out at the same time by an economist at the Wharton School of the University of Pennsylvania, Edward Herman, published in a book we co-authored in 1979. Herman studied the relation between torture and foreign aid worldwide, finding that the same correlation held: states that engage in torture are more likely to receive U.S. aid. But Herman also did a second study which offers a plausible explanation for the correlation. He compared U.S. aid with the climate for business operations, finding that the two were closely correlated. That makes sense. Foreign aid, after all, is largely a device whereby the U.S. taxpayer subsidizes U.S. corporations via some other country, which may incidentally gain from the process. Resorting to this device increasingly as opportunities for profit improve is completely natural, given the sources of policy-making."