The research, carried out by The Guardian, found that in 102 out of a total of 464 incidents registered in 2015, people killed by the US police were unarmed.
Among them, almost every third person was black, while 15 percent were white and 25 percent were Hispanic or Latino.
Among a total number of those killed by police, 29 percent were black US citizens, which shows how disproportionately fatal incidents involving black people falling victim to US police occur. Black people make up 13 percent of the total US population, according to the US census bureau.
Well-documented civil unrest broke out over a case in Ferguson, Missouri, late 2014 after a jury chose not to indict a white officer who shot and killed an unarmed black teenager.
The most recent unrest took place in Ohio about a week ago, when Cleveland police arrested 71 people during a day of violent protest after a white officer was acquitted of wrongdoing in his killing of an unarmed black couple in 2012.