After a US district court judge rejected a key witness of the prosecution, the first trial of a Guantanamo Bay detainee in a civilian court began on Wednesday.Judge Lewis Kaplan had last week refused to admit the witness since prosecution learnt about the witness from information procured through torturing the defendant, Ahmed Khalfan Ghailani, in an overseas jail run by the CIA.Ghailani who has spent the last six years in “black sites” and Guantanamo Bay, is accused of participating in the bombing of US Embassies in Kenya and Tanzania in 1998, which killed 224 people. Lewin said an al-Qaeda cell connected with Osama bin-Laden was responsible for both of the bombings.On the other hand, Ghailani's attorney Steve Zissou declared him innocence.