We found them by simple looking at the IP that the packets of the captcha were served from. The captcha was served over tor, based on the evidence that's impossible. Either you lied or you need to add further evidence. If you can't/won't add further evidence then as the court sees it you lied and are in contempt and will be punished in line with minimum sentencing??
This is of the order of a "he robbed me at home at exactly 2pm", "your submitted cell-phone evidence says you were at work from 1pm until 4pm".
If the defendant is convicted on some other counts can they, or anyone else, do anything or is the allowance of officers of the FBI to lie in open court somehow embedded in the USA constitution.
As a foreigner to the USA this sort of thing just undermines the entire foreign policy rhetoric of bringing democracy to the world. Bring some damned democracy to the USA first: government by the people for the people, my arse.