Two young black men shot dead by police in New York City and Cincinnati puts number killed by police in the US on track to exceed 1,000 by end of 2015

The number of people killed by police in the United States during 2015 reached 500 on Wednesday, according to a Guardian investigation, after two young black men were shot dead in New York City and Cincinnati.

Isiah Hampton, 19, was fatally shot by New York police department officers at an apartment building in the Bronx on Wednesday morning, according to police chiefs. His death followed that of Quandavier Hicks, 22, during a confrontation with Cincinnati officers at a house on Tuesday night.

Their names were added to The Counted, a project by the Guardian to report and crowd-source names and a series of other data on every death caused by law enforcement in the US this year.

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The federal government does not currently keep a comprehensive record of people killed by police. Instead the FBI runs a voluntary program to submit numbers of “justified homicides”.

The updated findings on fatalities so far this year means that the total is on track to exceed 1,000 by the end of 2015 – and that people are being killed by officers at more than twice the rate most recently detected by the much-criticised FBI system, which recorded 461 killed in 2013.

While the number of African Americans killed by police so far in 2015 has been disproportionately high, both white and Hispanic/Latino Americans now make up proportions of those killed that are smaller than their shares of the general US public.

Among the first 500 deaths, 49.6% of people were white, 28.2% were black and 14.8% were Hispanic/Latino. According to the 2013 census, the US population is 62.6% white, 13.2% black and 17.1% Hispanic/Latino.

Hampton on Wednesday allegedly confronted officers who had arrived at a Bronx apartment building in response to a 911 call reporting a man with a gun, according to authorities. The NYPD said Hampton, who was identified by several New York media outlets, had shot and pistol-whipped the mother of his two-year-old child during a domestic dispute.

“The female was able to pull away from the male,” James O’Neill, the NYPD’s chief of department, said in a statement. “The male was still pointing the gun at the officers, and a sergeant and one officer fired multiple rounds at the male.”

A night earlier, Hicks allegedly confronted four Cincinnati police officers with a rifle as they knocked on doors to investigate a call alleging he had been menacing. Witnesses, however, complained that police kicked in the door to the building where they found Hicks.

More than one in every five people killed so far in 2015 – 108, or 21.6% – were unarmed. A significant disparity in the proportion of black and white people killed who were unarmed, which was reported last week by the Guardian, has since narrowed slightly. While 30.5% of black people killed were unarmed, 16.1% of white people killed had no weapon.

Men comprised 95.2% of the first 500 people killed, while 4.8% were women. There are slightly more women than men among the general population.

Christie Cathers, a 45-year-old West Virginia woman, is the only woman to have been killed by police since the launch of The Counted last week. Cathers was shot by Monongalia County deputies while shooting at them during a vehicle chase, according to authorities. She allegedly tried to strike a deputy with her vehicle when officials responded to a complaint of a woman brandishing a knife.

• This article was corrected on 17 June 2015. It previously stated 30.5% of white people killed were unarmed while 16.1% of black people killed had no weapon. The figures had been reversed.