The man who led a plot to bomb New York subways in 2009 told in a Brooklyn federal court Wednesday that he was trained to make explosives at an al-Qaida compound in Pakistan and he had no issues killing innocent people, even babies, in the attack.

Najibullah Zazi, who pleaded guilty to his crimes, appeared as a government witness in the prosecution of an accomplice.

"We needed to send a message to the United States, especially Obama," Zazi testified.

In exchange for a reduced prison sentence, the 27-year-old Zazi agreed to cooperate with federal investigators in the prosecution of his alleged accomplice and former high school classmate, Adis Medunjanin.

Medunjanin, 28, is accused of conspiring to kill U.S. troops in Afghanistan, providing material support to al Qaida and plotting to use weapons of mass destruction on American soil. He claims that he backed out of the plot.

Zazi accepted most of the responsibility for the plot, saying he and convicted co-conspirator, Zarein Ahmedzay handled more details because they were better liars than Medunjanin.

Nevertheless, both Zazi and Ahmedzay, who also testified against Medunjanin, admitted that the three men traveled to Pakistan in August 2008 where they were trained at an al-Qaida compound in Waziristan. The men reportedly watched videos of al-Qaida attacks on the Danish embassy in Pakistan in 2008 and on the London Subway in 2005, and Zazi also learned to make explosives.

Zazi also testified to recording a "martyrdom video" while in Pakistan that was set to be released after his suicide operation.

"I just read Koranic verses and said some mentions about Afghanistan and Iraq and atrocities. 'This was payback for the woman that was gang-raped in Iraq'" he said.

Defense lawyer, Robert Gottlieb, asked Zazi if he thought it was moral to kill people on the subway.

"In America, yes," Zazi replied.

Despite his crimes, Zazi insists he can change.

"I hope for a second chance," Zazi said. "I believe my crimes were very bad. If God gives me another chance I would appreciate it and I will be a very good human being."