An ISIS leader who was one of five terrorists captured in Iraq last week was reportedly behind the execution of a Jordanian pilot who was burned alive in a cage in 2015.

Saddam al-Jamal is believed to be the mastermind behind the harrowing execution of Jordanian pilot Muath Al-Kaseasbeh, who was shot down and captured in Syria in December 2014 and was seen being burned alive in a cage months later, The Daily Mail reported Tuesday, citing Jordanian authorities.

The video, which Jordan said was authentic, showed al-Kaseasbeh standing in a cage with a line of fuel leading to him, which then ignited, causing him to burst into flames. ISIS previously sought to trade Al-Kaseasbeh for Sajida al-Rishawi, an Iraqi woman who is in a Jordanian prison for her role in a 2005 suicide bomb attack that killed 60 people in Amman.

Al-Jamal was the most prominent ISIS militant captured in a cross-border raid last week. The arrests were a “significant blow to [ISIS],” coalition spokesman Col. Ryan Dillion said.

Islamic State militants poured into Iraq in the summer of 2014, taking control of nearly a third of the county and at the height of its power, their so-called caliphate stretched from the edges of Aleppo in Syria to north of Baghdad.

The heyday of ISIS in the Middle East is long over. Al-Jamal said in a video released by Iraq’s intelligence agency that the group was in a “bad state,” according to The Wall Street Journal.

“There are many divisions and internal struggles within the organization,” he said. “Many of the fighters have lost the will to fight.”

Al-Jamal has been accused of being one of the most notorious killers in the Middle East.

He has been accused of taking part in a 2014 massacre in Syria that killed 700 members of a tribe that tried to stand up to ISIS and Iraqi officials believe he slaughtered an entire family that sought to stop their daughter from marrying him, according to Metro UK.

The Associated Press contributed to this report.