In New York, the Police are searching for a woman who fired the weapon on a busy street of Franklin Avenue in Crown Heights, Brooklyn on Wednesday.
Officials identified the victim as 42-year-old Delia Johnson, who suffered a serious gunshot in the head and wounds on the leg. She was rushed to a hospital where she later died from the injuries.
Surveillance camera footage released by the officials shows Delia standing in front of a shop on the street where a group of people hangs around.
The suspect, described as a dark-skinned adult female in her mid-20s, walks up behind Delia and pulls out a handgun before firing a shot towards the back of her head.
Delia falls to the ground and the gunwoman turns around and gets in a white car, which then flees the scene.
Officers patrolling nearby arrived within moments and found a faint pulse and began performing CPR despite the victim lying unconscious and unresponsive.
She was taken to a hospital where doctors pronounced her dead.
Delia's brother, Mathis Johnson, told the Daily News that the attacker may have followed his sister from the funeral of a pal earlier in the day.
He said: "She was at a funeral earlier in the evening for an old neighbourhood friend to pay her respects, and then this happened.
"It was horrible. That lady executed my sister."
"The woman was heartless, she took a sister, a daughter away, she took a mother."
Investigators have a possible suspect ID but have not yet made an arrest, a police source told Fox News.
New York Police said the shooter was with a heavy build and long blonde hair. She was last seen wearing a black long-sleeve shirt, black tights, a silver belt, black and white sneakers, and a white purse.