505 Americans have already been shot dead by police this year. It is reports like those from the state of New Jersey that shake confidence in state authority. Hispanic Witney Rivera was wounded by light-skinned police officers a few days ago after an argument with his wife, and died a little later in hospital. A neighbor reported: "He was already on the ground, but they kept shooting at him." Such messages are almost everyday in the US, they reinforce the image of the trigger-happy and racist white cop who just shoots people with dark skin and is not prosecuted for it.

However, a study by the universities of Maryland and Michigan State in the journal contradicts the thesis that fair-skinned police officers shoot people with a different skin color more often than their dark-skinned and Hispanic American colleagues Proceedings of the National Academy of Sciences. Statistically, it is rather the case that "African Americans are more likely to be shot by black police officers," says Joseph Cesario, professor of psychology at Michigan State University, one of the authors of the study. "A change in the structure of the police, in other words more non-fair-skinned officers, should therefore not lead to fewer dark-skinned deaths."

The researchers' second finding: the more violent crimes committed in an area by members of a certain population group, "the higher the likelihood that a person of that skin color will be shot by the police," says Cesario. This applies to whites as well as to blacks and Hispanic Americans. "An effective strategy to reduce the death toll among black people and Hispanic Americans should be to reduce racial violent crimes." However, the study also says that if you look at the fatal shots by police nationwide, it is 3.7 times as likely to hit African Americans and 3.3 times as likely to hit Hispanic Americans as whites.

So are milieus the problem and not the cops? When discussing police violence, a number from 2015 is often given. At the time, 12 percent of the US population were African American - but they accounted for 26 percent of the fatalities from police firearms. According to a data project by the British newspaper The Guardian a young African American was nine times more likely than the rest of the Americans to be killed by police that year. Dark-skinned men aged 15 to 34, although just two percent of the total population, made up 15 percent of the victims in 2015.

The US researchers, however, describe statistics like these as insufficient to establish a causal connection to the skin color of the police officers. Using data from various newspapers and their own research in US districts, they evaluated 917 deaths from gunfire. Nevertheless, the work "does not allow any conclusions to be drawn about individual cases, it neither accuses an official nor acquits him," emphasizes Cesario. "The study does not serve to draw conclusions about racism." The public perception that racism is a widespread problem facing the American police force will not be dispelled by the findings.

In addition, the psychologists only examined cases in which someone died. Injuries or conflicts that were resolved without a weapon do not appear in the study. However, the researchers are also proving another imbalance that has hardly been discussed so far. The scientists also evaluated the sex of the officers. In 2015, the American police force was around twelve percent women. Fatal shots were fired by male police officers in 96 percent of the cases. Perhaps it would help to adapt the structure of the police force - not just in terms of skin color, but also in terms of gender.