In this handout image made available by the photographer American journalist Steven Sotloff (Center with black helmet) talks to Libyan rebels on the Al Dafniya front line in Misrata, Libya on June 02, 2011. Sotloff was kidnapped in August 2013 near Aleppo, Syria. (Etienne de Malglaive via Getty Images)

The Islamic State of Iraq and Syria, or ISIS, has murdered American journalist Steven Sotloff, releasing a video yesterday appearing to depict the kidnapped journalist’s beheading. It’s similar to a disturbing video that surfaced online two weeks ago, which showed the murder of journalist James Foley, and which led President Barack Obama to call ISIS a “cancer” that must be extracted.

President Obama confirmed the authenticity of the new video during a press conference in Estonia. “Overnight, our government confirmed that, tragically, Steven was taken from us in a horrific act of violence,” he said Wednesday.

Last week, Sotloff’s mother pleaded with ISIS to spare her son after he appeared on-screen in the Foley video. Shirley Sotloff posted a video online directed to Abu Bakr al-Baghdadi, the organization’s self-proclaimed caliph, or spiritual leader, asking him “to be merciful and not punish my son for matters he has no control over.”

Sotloff, 31, disappeared in Syria one year ago while covering the conflict in the Middle East as a freelancer for Time magazine and other publications. He grew up in the Miami area, where he attended Jewish day school at Temple Beth Am, and later studied journalism at the University of Central Florida.

According to JTA, Sotloff had held dual American-Israeli citizenship, though that fact, in addition to his ties to the Jewish community, had been kept under wraps while he was captive.

The Foreign Ministry cleared for publication Wednesday that Sotloff, 31, held Israeli citizenship. His connections to Israel and the Jewish community reportedly had been sanitized from the Internet and social media in order to keep the information from his radical Islamic captors.

YNet reports that Sotloff’s captors didn’t know he was Jewish. According to a fellow hostage, Sotloff pretended to be ill so he could fast for Yom Kippur without arousing suspicion.

“He told them he was sick and doesn’t want to eat, even though we were served eggs that day,” the friend told the paper. “He used to pray secretly in the direction of Jerusalem. He would see in which direction (his Muslim captors) were praying and then adjust the angle.”

British authorities have been racing to identify the ISIS militant who appears in both videos, and the British ambassador to the U.S. said on August 24 that counterterrorism officials were close to identifying the man.

Previous: Obama Confirms ISIS Murder of U.S Journalist