Video Claims to Show Beheading of U.S. Reporter Steven Sotloff by ISIS

The Islamic State in Iraq and Syria has beheaded Steven J. Sotloff, the second American executed by the Islamic militant group, and posted a video of it on the Internet, the SITE Intelligence Group, a research organization that tracks jihadist web postings, said Tuesday. Mr. Sotloff’s family issued a statement saying it believed he had been killed.

The execution of Mr. Sotloff, 31, came despite pleas from his mother aimed directly at ISIS’s top leader seeking mercy for her son, a freelance journalist who was captured in northern Syria a year ago.

Word of Mr. Sotloff’s beheading came two weeks after James Foley, 40, another American journalist, was beheaded by ISIS, which warned that Mr. Sotloff would be the next to die.

The videotaped beheadings and threats by ISIS have helped rocket the group’s ascendance into a top crisis for the Obama administration and its Western allies.

Mr. Sotloff’s family members issued a statement via a spokesman, Barak Barfi, that suggested they believed the video was authentic: “The family knows of this horrific tragedy and is grieving privately. There will be no public comment from the family during this difficult time.”

Josh Earnest, a White House spokesman, said he could not immediately confirm the authenticity of the video showing Mr. Sotloff’s killing. “It is something that will be analyzed very carefully by the U.S. government and our intelligence officials to determine its authenticity,” he told reporters in Washington.

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