Convicted terrorist Omar Khadr’s appeal to drop war crime convictions and reverse a guilty plea for crimes he committed when he was 15 years old was shot down by the U.S. Supreme Court.

The court’s decision was divided, but ultimately, a three-judge panel rejected his appeal on Monday.

The judges decided that Khadr gave up his right to judicial review when he pleaded guilty in 2007 to five war crimes, including throwing a grenade that killed U.S. Sgt. Christopher Speer on July 27, 2002, in Afghanistan.

Khadr also pled guilty to attempted murder in violation of the law of war and providing military support to terrorism when he was 24.

He has since challenged his previous convictions despite the guilty plea.

The bargain he struck in 2012 allowed him to be extradited to serve eight years in a Canadian prison instead of 40 years in U.S. custody.

Khadr was sentenced to eight years in Canadian prison in addition to the nearly ten years he spent as a prisoner at Guantanamo Bay in Cuba.

The U.S. argued that Khadr hasn’t disputed any of the factors that led to his guilty plea, and his material support to a terrorist entity charge, in particular, has not been disputed either.

Khadr’s team argued that in a decision by the United States Court of Appeals involving another Guantanamo Bay inmate, Salim Ahmed Hamdan, in 2012, charges for material support of terrorism were dismissed because it was not a crime until 2006.

Khadr was captured on the scene of the battle in 2002.

His team argued that his plea bargain was based on the assumption that providing material support to al-Queda was a crime. They claimed that Khadr should be granted a judicial review on those grounds.

Khadr was 15 years old when he committed the crime, he was brought to Afghanistan by his father Ahmed, an al-Queda financier with connections to Osama bin Laden.

While Khadr was at a suspected al-Queda weapons supply site, a firefight between the international terrorist group and U.S. military forces broke out. During the clash, Khadr threw a grenade killing Speer.

After being captured by the U.S. forces, Khadr became the youngest detainee to be held on terror charges at Guantanamo Bay.

Justin Trudeau’s Liberal government granted $10.5 million of taxpayers’ funds to Khadr in July 2017, citing human rights violations at the US-run detention centre. However, allegations of human rights abuses have not been proven in court.

Khadr said his guilty plea was brought out as a result of the torture he faced at the hands of the U.S. government at Guantanamo Bay.

After Speers family sought a $134 million settlement from Khadr in a wrongful death ruling from a Utah court in 2020, an Ontario court ordered Khadr to answer precisely what parts of his testimony were false.

The family’s lawyers want Khadr to go “fact by fact” through his confessions to give the family of the victim the truth about what happened.