The prosecution‘s case was dealt a major blow when a witness said that it was he, not Gallagher, who had put an end to the captive ISIL fighter‘s life.

Corey Scott, a first class petty officer, testified that while he had seen Gallagher stab the wounded fighter in the neck in May 2017, he had killed the boy afterwards.

He testified that he covered the victim‘s breathing tube with his thumb and then watched him die.

Scott said he did so to spare the boy – who prosecutors say was about 15 years old – from suffering or being tortured by Iraqi forces.