Many on January 22 referred to him as a "hero" and "Euromaidan's first martyr." One woman recounted on Facebook how she met him after bringing hot tea to the protest: "Unlike a lot of the other guards, he didn't approach me—he didn't leave his post. I walked up to him myself, and only then he took the tea and gratefully kissed my hand."

Many supporters circulated a video showing Nihoyan standing at the protests and raising a clenched fist as he recites the following passage from "The Caucasus," a poem by Ukraine's 19th-century poet and artist Taras Shevchenko that depicts the struggle of Circassians to free themselves from Russian oppression:

And glory, freedom's knights, to you,

Whom God will not forsake.

Keep fighting—you are sure to win!

God helps you in your fight!

For fame and freedom march with you,

And right is on your side!

Above: Serhiy Nihoyan reads "The Caucasus" in Ukrainian.

Serhiy Proskurnia, a Ukrainian filmmaker who has produced a series of the Shevchenko videos to mark the 200th anniversary of the poet's birth, says he was struck by Nihoyan's charisma.

"He enthusiastically agreed to take part in our project," Proskurnia says. "For me, it was very interesting because he was an Armenian who spoke very good Ukrainian. He fulfilled all my producer's recommendations—this 'rot front' gesture, the raised hand with a tight fist, and two flags, Ukrainian and Armenian. This clip has made him recognizable; a lot of people noticed him. Now, unfortunately, it's become the main clip of our project."

Other observers, however, have attempted to cast doubts about Nihoyan's background, with several tweeting journalists and at least one blogger, Graham Phillips, suggesting Nihoyan was a paid mercenary or right-wing terrorist trained by members of an Armenian liberation movement. Phillips offers no evidence to back his claims but includes a link to Nihoyan's VKontakte page, which contains photographs of Nihoyan in combat fatigues, holding a gun and in some cases brandishing an Armenian flag.

Defenders have argued that the pictures are likely from Nihoyan's one-year military service, which remains obligatory for young men in Ukraine. Other pictures show Nihoyan holding the Armenian flag in a variety of settings, including at the beach. Still others show him at the Euromaidan protests, in one instance holding a placard reading, "God speaks through the voice of the people."

Above: Nihoyan's father speaks about his son.

"He loved history, both Armenian and Ukrainian," said his mother, Venera, saying that he remembered to light a candle every December 7 in memory of Armenia's devastating Spitak earthquake in 1988. "That's the kind of guy he was. He had never been to Armenia. But he dreamed of getting a passport and getting to travel there."

The Kyiv Post quotes Oleh Musiy, the coordinator of medical services for the Euromaidan demonstration, as saying Nihoyan had been shot four times, including in the head and neck. He strongly suggested that conventional bullets had been used in the shooting. (Ukraine's Interior Ministry has denied responsibility for the killings, saying the guns used by their forces were loaded with rubber bullets.)