New details emerge in police shooting of 13-year-old New York boy

As the family of a 13-year-old boy who was killed by police in Utica, New York, demanded justice, the city's police chief alleged Monday that the teenager had a realistic-looking replica gun still in his hand when he was shot.

The boy, identified as Nyah Mway, was shot once in the chest by a Utica police officer on Friday night after he and a friend were stopped on a street by officers investigating a robbery pattern, officials said.

"This is very heartbreaking for the family because they lost a child," Mway's uncle, Lay Htoo, told ABC News, adding that his nephew recently graduated from the eighth grade.

Htoo said the shooting had devastated his family, who moved to Utica eight years ago after escaping civil unrest in Myanmar and spending time in a refugee camp in Thailand.

He said the family came to America to avoid violence, only now to be confronted by it.