He also provided testimony to S.E.C. investigators.
He has already provided testimony to securities regulators in a parallel civil inquiry.
Eighteen witnesses provided testimony on Monday, officials said; no details were provided about Tuesday's hearing.
One of the witnesses, a man with the code name "Jennifer," also provided testimony against General Dauahare.
Andy Pettitte, the Yankees pitcher and another government witness, also provided testimony that probably damaged the government's case.
"Wherever the data takes us, we just tell the truth," said Stephen Wistar, a senior forensic meteorologist for AccuWeather, whose experts have provided testimony in hundreds of courtrooms.
Half a dozen witnesses also provided testimony supporting Mr Wilson's version of the events.Others, however, allege that Brown was shot with his hands up.
According to a person with knowledge of the case, the riders who provided testimony include several top American cyclists of Armstrong's generation.
His lawyer, Chris Manderson, said that Hamilton had received a grand jury subpoena but did not say whether Hamilton had already provided testimony.
"This is a decades-old divorce case in which Mitt Romney provided testimony as to the value of a company," the lawyer, Robert Jones, said.
