Security camera footage of the cold-blooded killing of a 32-year-old man by a deranged bystander in Brooklyn, New York, early Monday morning is making the rounds online.

The young man was sitting with a female friend at a bus stop – they were returning from a wedding dressed up and talking. At some point a man in a dark hooded sweatshirt with his hands in his pockets passes them.

After a while the couple get up and casually walk in the same direction as the unknown man, who is a few meters in front of them. The perpetrator suddenly and furiously starts kicking some skates and turning around sees 32-year-old Carson a little behind him.

“What are you looking at, I’m going to kill you” he asks fiercely and moves menacingly towards the couple. “Nothing calmed down” says the 32-year-old and steps between the furious man and the girl to protect her.

The assailant then chases after Carson wielding a knife, while the victim’s girlfriend runs after them shouting “please, please, please!”.

Ryan Carson stabbed

The 32-year-old falls on the bench he was sitting on a while ago, the attacker catches up to him, throws him to the ground and stabs him to death. Shadow is then seen verbally attacking the girl, who is looking blank.

The perpetrator leaves the shot and another woman – known to the perpetrator – appears shouting “Don’t bother him!” and repeating a name that sounds like “Bryan”.

He then approaches the young man on the ground and his girlfriend saying “I’m so sorry!”. Her girlfriend says “go watch him” and calls 911.

The unfortunate 32-year-old was rushed to Kings County Hospital Center, but it was too late – as the knife had gone through his heart, according to police and sources.

As of Tuesday afternoon, no arrests had been made and the police have not even found the deadly weapon.