Jack Hensley, 48, American civilian contractor, beheaded by Muslim terrorists in Iraq.

The victim is believed to be Jack Hensley.

In the video, a militant repeated a death threat against the other hostages, saying the other American seized with Mr. Armstrong, Jack Hensley, could be killed within 24 hours.

The group, One God and Jihad, announced Tuesday that it had beheaded a second American hostage, Jack Hensley.

The United States Embassy identified the two Americans as Jack Hensley and Eugene Armstrong, also known as Jack.

Jack Hensley of Marietta, Ga., is the remaining American hostage from the three construction workers who were taken from their house in Baghdad.

Their guards were leaving one by one because of death threats, Jack Hensley had written, and he believed the three Westerners were being watched.

The group threatens to behead two additional hostages, American Jack Hensley and Briton Kenneth Bigley, within 24 hours unless the United States meets its demands.

The two Americans kidnapped with Mr. Bigley, Eugene Armstrong and Jack Hensley, were beheaded.

Mr. Bigley was kidnapped last week along with the two Americans, Eugene Armstrong and Jack Hensley, from a house in an upscale neighborhood of Baghdad.