The corrections I made were as follows

The former School of the Americas had been criticized for the participation in human rights violations by (many changed to)some of its graduates. It cannot be logically maintained that many is the proper choice for the word when were talking about a handful of names out of an estimated 61,000 graduates.


I also added


(Although there is no direct cause and effect evidence to prove their claims critics) argue that the education received at the school encourages such practices. In response to their critics WHINSEC developed a course on human rights protections and requires the training be taken by their students .[8

Unless the person who posted the statement is willing to clarify that some of the training of accused human rights violators was is subjects such as logistics (handling of supplies) and other such subjects which could not possibliy have influenced or encouraged the student in any way to commit human rights abuses.