Start here: Latest developments in the fight against ISIS

THE BRUTALITY

Burned alive: Every few days, it seems as though ISIS ups the ante on its savagery. Wednesday brought news that the militants killed at least 40 police officers and tribesmen in a town they recently seized in Iraq’s Anbar province — and that most of the victims were burned to death. That’s according to an Iraqi official. CNN hasn’t independently confirmed the account. The Pentagon says it’s looking into it.

Speech analysis: Just as it’s doing with “Jihadi John,” the intelligence community is trying to figure out the identity of the new English-speaking executioner in the video ISIS released showing the beheadings of the Egyptian Christians. The most intriguing clue is in his voice: The accent appears to be either American or Canadian.

CNN’s Richard Roth, Jim Acosta, Sarah El Sirgany, Tim Lister, Jim Sciutto, Barbara Starr, Jomana Karadsheh, Salma Abdelaziz, Atika Shubert and Catherine E. Shoichet contributed to this report.

CNN