Steven Sotloff, the second American purportedly beheaded by ISIS

Steven Sotloff, the American journalist who was seen at the end of the video that showed the beheading of James Foley by the Islamic State of Iraq and the Levant, has been executed, a new video released by the militant group purports to show.

Here is what we know about Sotloff so far.

In a two-sentence statement, family spokesman Barak Barfi said Sotloff's family, "knows of this horrific tragedy and is grieving privately."

The video comes less than a week after Sotloff's mother issued a desperate plea to the group's self-proclaimed leader, Abu Bakr al-Baghdadi, to spare her son.

"Steven is a journalist who traveled to the Middle East to cover the suffering of Muslims at the hands of tyrants,” Shirley Sotloff said in the videotaped message broadcast on al-Arabiya TV.

“He is an honourable man and has always tried to help the weak.

"Steven has no control over the actions of the US government," she continued.

"He’s an innocent journalist. I’ve always learned that you, the caliph, can grant amnesty. I ask you to please release my child. As a mother, I ask your justice to be merciful and not punish my son for matters he has no control over."

It's unclear by the released video when Sotloff's apparent execution occurred.

In a Facebook message, Frank Castle, the boyfriend of Sotloff's sister, asked supporters to sign a petition calling for his release.

"MY GF Lauren Sotloff's brother Steven Sotloff was taken hostage by ISIS on August 04 2013 and up to this point it has been all under wraps," Castle wrote.

"People please not only sign the following petition, but PLEASE SHARE soo the more the better. Thank you in advance & pray for his safe return home."

Lauren Sotloff did not immediately return a Facebook message seeking comment.

Sotloff, 31, was a freelance journalist from Miami whose work had appeared in Time magazine, Foreign Policy and the Christian Science Monitor.

He went missing in Aleppo, near the Syrian-Turkish border, in August 2013.

Sotloff's last published piece appears to be a July 2013 column about Egypt ('Opposing Morsi but Defending Democratic Legitimacy') for World Affairs magazine:

As I stumbled over the sandals and the men sleeping next to them at the Raba’a al-Adawiyya mosque in Nasser City, where the Muslim Brotherhood is holding its daily rallies, the beards and headscarves blended into a blurry monochrome pastel. But as I looked closer into a sea of Egyptians that Moses would have been hard pressed to part, one man’s tresses caught my attention. A cross between Don King’s stand-at-attention locks and Julius Erving’s flapping waves, they drew me in like a siren call.

His last piece for Time ('Libya’s New Crisis: A Wave of Assassinations Targeting Its Top Cops') was published in late 2012.

A friend, Ann Marlowe, tweeted that Sotloff "lived in Yemen for years, spoke good Arabic, deeply loved Islamic world.. for this he is threatened with beheading."

According to his LinkedIn profile, Sotloff was a graduate of the University of Central Florida. His Twitter bio says he was last based in Libya; his most recent tweet, on August 3, 2013, is about the Miami Heat.

A few days before, Sotloff tweeted that he had been pepper-sprayed by police in southern Turkey.

Janine di Giovanni, Newsweek's Middle East editor of Newsweek who worked alongside Sotloff in Syria, described him this way:

Sotloff is young and funny and irreverent. He lived in Benghazi, Libya—he actually lived there—one of the few freelance reporters who felt he had to stay there to do his job properly. He is a great storyteller, but he is also smart and committed. A few days after he disappeared, I got some strange private messages from him on Facebook. They turned out to be from the friend he had been with who had found his computer. It was eerie. While Foley’s abduction had gone public — his family had made that decision, believing it would help locate him — Sotloff’s had been quiet. Some of us tried to find information about what happened to him, but it was as if he had simply disappeared off the face of the earth — which he had.

On July 27, 2013, Sotloff posted a photo of Abdelsalam al-Mosmary, a lawyer and prominent Libyan activist, posing with two children in front of a car adorned with Libyan flags (and a New York Yankees decal, placed upside-down) on his Facebook page. The day before, al-Mosmary was killed by a sniper's bullet while leaving a Benghazi mosque.

Morning news break – September 03