Search for Clues to American Peter Kassig's Death in ISIS Video

— -- For the third time since August top U.S. officials, including President Obama, have been forced to offer their condolences to an American family for the death of their loved one at the hands of ISIS – this time aid worker Peter Kassig, whose dismembered head was seen in a gruesome video released this weekend.

Kassig, who changed his first name to Abdul-Rahman after converting to Islam, is the third American and the fifth Western hostage to be beheaded by the terror group and then shown on camera. But while the other videos followed a twisted, yet fairly set routine, Kassig’s is very different – and may offer intelligence analysts important clues about Kassig's last moments, the status of other hostages and what effect the coalition push against ISIS is having.

“We look for patterns, which clearly they went away from with this video,” a U.S. military intelligence analyst told ABC News today. “If they were comfortable with how things are going, they would have stuck to it. The pressure’s on.”

So what’s different about the Kassig video?

Kassig Is Never Seen Alive

Beginning with the first on-camera murder of American journalist James Foley in late August, in each of the execution videos the condemned man is seen alive and apparently reading a statement critical of U.S. or British actions against ISIS. The video then cuts to a statement made by a black clad figure with an English accent and then cuts again, this time to the actual execution. The beheadings themselves were not shown, but the severed head of the victim is shown placed on top of the body.

In Kassig’s video, however, he is never shown alive and only his head is visible, opening up a myriad of possibilities as to how he actually died.

Mitchell Prothero, McClatchy’s Iraq correspondent and former roommate of Kassig’s in Beirut, said he suspected Kassig refused to participate in the scripted readings.

“Clearly something went wrong. Peter was a high-value prize for them,” Prothero said in a McClatchy report. “My belief is that he knew it was up and did something to screw up their video.”

The black clad figure, who the FBI believes they’ve identified, does make a statement similar to those he made before, but in this one he references Kassig’s prior military experience fighting for the U.S. Army in Iraq. The figure has previously not discussed the victims’ personal lives.

No Potential Next Victim Shown

At the end of previous videos, ISIS has always shown the next hostage they plan to execute. Kassig was seen at the end of the video showing the death of British aid worker Alan Henning a month ago.

But in the newest video, no other hostages are shown alive and no further threats of murdering hostages are made. ABC News has previously reported that ISIS is believed to be holding at least one more American hostage, a 26-year-old female aid worker.

Earlier, ISIS Shows Multiple Beheading

In another departure, ISIS uses the latest video to show other horrifying apparent crimes, including the mass execution of more than a dozen purported Syrian soldiers by knife-wielding, unmasked ISIS members. The French government believes it has identified one of the men shown as a French citizen.

Previous videos of Western hostages were dedicated to that single act, but Kassig is only seen near the end of the last 16-minute film.

Significance of Location Change

Though the location of previous videos has changed before – the background desert from the Foley video was different than that of the death of Steven Sotloff – the Kassig video has a location marker identifying it as being shot in Dabiq, a town in northern Syria, and buildings are visible in the background. Based on the buildings, an anti-ISIS Syrian activist group said the video was likely shot just north of town.

Previously, Western hostages were believed to have been held in or near Raqqa, Syria, a stronghold for ISIS and the location of a failed raid this summer by U.S. special operations forces to rescue them.

If Kassig was indeed killed in Dabiq or his remains brought there, it could be a highly significant move for the terror group. In an ancient Muslim prophecy attributed to the Prophet Muhammad, Dabiq is to be the scene of a final battle between the Muslim and infidel crusader armies.

“The Prophet predicts the Day of Judgment will come after the Muslims defeat Rome at al-`Amaq or Dabiq, two places close to the Syrian border with Turkey,” William McCants at the Brookings Center recently wrote. “Another prophecy holds that Rome’s allies will number 80.”

In the new video, the black clad figure addresses President Obama as the “dog of Rome” and says, “Here we are burying the first American crusader in Dabiq, eagerly waiting for the remainder of your armies to arrive.”

ABC News’ Molly Hunter contributed to this report.