Steven Sotloff, the man beheaded in a video released by ISIS on Tuesday, was a grandson of Holocaust survivors who lived in Miami, and was a dual American-Israeli citizen. That fact was confirmed by an Israeli official on Wednesday afternoon. Sotloff, who received his degree from IDC in Herzliya, a school where many local families send their children, was known to have fasted on Yom Kippur during his captivity and would pray facing Jerusalem.

Sotloff freelanced for Time and Foreign Policy magazines among others, and was last seen in Syria in August 2013 until he appeared in the video that showed the brutal murder of James Foley.

The beheading, according to ISIS, was a reprisal for U.S. air strikes in Iraq, and the image is authentic, U.S. National Security Council spokesperson Caitlin Hayden said on Wednesday. The video, entitled “A Second Message to America” shows Sotloff in an orange jumpsuit similar to the one James Foley wore before he was beheaded. The murdering terrorist appeared to be the same British-accented man who appeared in an Aug. 19 video of Foley’s brutal execution, and showed the same type of landscape.

In it, the terrorist threatens a British citizen named David Haines, and said he was next unless governments back off “this evil alliance of America against the Islamic State.” He also said, “I’m back, Obama, and I’m back because of your arrogant foreign policy towards the Islamic State, because of your insistence on continuing your bombings and… on Mosul Dam, despite our serious warnings.”

Before his execution, Sotloff spoke into the camera: “I’m sure you know exactly who I am by now and why I am appearing. …Obama, your foreign policy of intervention in Iraq was supposed to be for preservation of American lives and interests, so why is it that I am paying the price of your interference with my life?”

Then the British terrorist, who is believed to be a rapper/disc jockey from London, said that as long U.S. missiles “continue to strike our people, our knife will continue to strike the necks of your people.”

President Barack Obama said Wednesday that the United States will not be intimidated by Islamic State militants after the beheading of a second American journalist and will build a coalition to “degrade and destroy” the group.

Sotloff’s mother Shirley appealed on Aug. 27 in a videotaped message to Islamic State’s self-proclaimed caliph, Abu Bakr al-Baghdadi, for her son’s release. Addressing him by name, she that her son was “an innocent journalist” who shouldn’t pay for U.S. government actions in the Middle East over which he has no control.

Sotloff was originally from Miami, where his family still lives. He majored in journalism, and although he didn’t finish his degree at Central Florida University, he continued his studies at the Interdisciplinary Center in Herziliya when he made Aliyah in 2008. He stationed himself in Yemen and learned Arabic, and became a reporter for Newsweek, Time, The Jerusalem Post, The Jerusalem Report, Israel Times, National Interest, The Christian Science Monitor, but all his editors kept his Judaism secret, because they thought it would be dangerous for him.

Janine Di Giovanni, Middle East editor of Newsweek, told CNN that Sotloff, who was a friend and colleague, was “very clever, he was very philosophical, he was aware of the risks.” He was also worried that he had ticked off Syrian rebels and that they’d put him on some kind of black list last year.

Josh Polsky, who was Sotloff’s roommate in college told the New York Times, “The guy lit up a room. He was always such a loyal, caring and good friend to us. If you needed to rely on anybody for anything he would drop everything on a dime for you or for anyone else. I felt like he really cared about it, he thought it was extremely important. He was very conscientious, enterprising and brave.”

Sotloff wrote reports from Bahrain, Egypt, Libya, Turkey and Syria. “A million people could have told him what he was doing was foolish, it seemed like it to us outsiders looking in, but to him it was what he loved to do and you weren’t going to stop him,” said his friend, Emerson Lotzia.