A musician shot dead three members of a band who had fled Iran and were turning heads in New York City for their music.
Two brothers in the band The Yellow Dogs were killed along with a singer, by a musician had recently been thrown out of a different group for theft.
Gunman Ali Akbar Mohammadi Rafie, 29, shot himself in the head at the end of his spree which has caused shock and dismay.
The Yellow Dogs had been marked out as up-and-coming by publications such as Rolling Stone and had garnered a fan base in America.
Members of the group fled Iran in 2010 to escape oppression in the country where rock music is banned by the state for being 'unIslamic.'
The shooting victims have been named as Soroush Farazmand, 27, his brother Arash, 28, and singer Ali Eskandarian, 35.
According to reports, Rafie - also known as Raefe Ahkbar - moved through a building in Brooklyn where they were staying and executed them in cold blood with a rifle.
Rafie killed Ali Eskandarian from outside the third floor of the building by firing through a glass door. He then climbed in to the building and shot Arash in the head. After this Rafie went downstairs and shot Soroush as he lay on a bed.
A fourth man was shot twice in the arm. Sasan Sadeghpourosko, 22, fled the scene and rang the emergency services. Meanwhile, Rafie had been confronted by another man and had fled up to the roof, where he shot himself in the head.
Friends paid tribute to guitarist Soroush, his drummer brother Arash and singer Eskandarian - who played with the Yellow Dogs on tour.
The killings took place while a film crew was shooting a documentary about the band. Film maker Kiernan Devine Jr said: "They are the warmest, most true hearted and idealistic group of young artists you could be lucky enough to know.
"The fact that they managed to escape from Iran and gain political asylum in New York City, finally able to chase their creative dreams - only to have this happen to them in our town - to be gunned down in their beds over a whole bunch of nothing. It is beyond any belief. It is madness."
Yanira Lantigua, a cashier at the local store where the men used to buy groceries, said brothers Arash and Souroush shared a close bond. "The brothers were inseparable. They were really nice kids."
According to reports, Rafie had fallen out with the band for stealing musical equipment and selling it on. The allegations saw him kicked out of a group named the Free Keys, which was described by the Yellow Dogs as "our sister band" by the Yellow Dogs.