The nation’s Public Safety Minister, Vic Toews, took months to decide whether Khadr was entitled to repatriation.

“I am satisfied the Correctional Service of Canada can administer Omar Khadr’s sentence in a manner which recognizes the serious nature of the crimes that he has committed and ensure the safety of Canadians is protected during incarceration,” Toews said in a statement.

Defense lawyers had asked that he get special protections at whichever Canadian prison was chosen because of his notoriety.

In his plea agreement, Khadr also admitted to planting landmines in Afghanistan meant to shred invading allied forces. Once captured, and interrogated, he directed U.S. troops back to their location to safely disarm them.

Testimony at pre-trial hearings showed U.S. interrogators saw the 15-year-old as a human intelligence treasure trove because as a child his family had spent time with the family of Osama bin Laden in Afghanistan. His father, Ahmed Said killed in Pakistan in 2003, was seen in Canada as a high-level al Qaida functionary who moved his family to Pakistan and Afghanistan in the years before the Sept. 11, 2001, attacks.

One of Omar Khadr’s elder brothers, Abdurahman, also spent a short time in Guantánamo as an informant but never saw his kid brother there. Abdurahman is now free in Toronto.

With Saturday’s transfer, the Pentagon now has 166 captives at Guantánamo.

The youngest is now believed to be a Yemeni named Hassan bin Attash, whose leaked detention records indicate he was born in Yemen in 1985. He’s the younger brother of former CIA captive Walid bin Attash, an alleged al Qaida lieutenant now at Guantánamo facing charges in the Sept. 11 death penalty case.

The Khadr transfer could break a logjam in efforts to get other captives to plead guilty. Defense lawyers have characterized the Obama administration’s inability to get Khadr back to Canada as an obstacle to negotiations with other alleged al Qaida foot soldiers whose testimony might be useful at the Guantánamo war court.

Amnesty International USA used the occasion of the transfer to urge President Barack Obama to close the detention center. “Khadr’s tragic story underscores why Guantánamo should close — not tomorrow, but today,” Amnesty Executive Director Suzanne Nossel said in a statement.

“Given the Obama administration’s glacial pace towards closing the U.S. controlled detention center, little and late though it is,” she added, “today’s news represents progress.”