Investigators Identify Account Behind James Foley's Execution Video

Investigators have reportedly identified the user of the account who uploaded the recent execution video of American photojournalist James Foley, a detail that serves as a "key part of the forensic trail" in tracking down Foley's murderers.

An authority with the U.S. counterterrorism operation reportedly told Fox News that intelligence officials have identified the user of the account, and believe the user is closely linked to top officials in the Islamic State, a jihadist group currently terrorizing Iraq in a quest for national power.

FBI authorities added to Fox News that investigators are looking into the video's audio to determine the voice of Foley's killer. Additionally, investigators have reportedly been observing the movements of Foley's murderer, including his manerisms and use of his left hand.

"Both the British intelligence service and FBI want a high degree of confidence in the match because lethal force is on the table," a U.S. counterterrorism source told Fox News.

In the gruesome video uploaded to YouTube last week, a member of the Islamic State is shown in an unknown desert location with Foley. The jihadist begins by demanding the U.S. immediately stop its airstrikes of Islamic State militants. Then, Foley is beheaded by his captor as an apparent warning to the U.S. to stop its attacks on the terrorist groups.

The United Kingdom has previously acknowledged that the speaker in the video is most likely of British decent, and as Fox News reports, the primary suspect involved in the video is 23-year-old British born rapper Adel Majid Abdel Bary.

Bary is the son of a high-ranking al-Qaeda leader, and earlier in August tweeted a photo of himself holding the head of a decapitated Syrian soldier.