We don’t know what was running through the mind of a Fort Worth police officer when he shot through a woman’s window while she sat playing video games with an 8-year-old child, killing her. Aaron Y. Dean, who has since resigned from the police force and been charged with murder, isn’t saying much about what led him to fire.

What we do know is that he was quick on the trigger and took an undercover SWAT sting approach to an incident that came in response to a wellness call on a non-emergency police line.

Mr. Dean and another officer overreacted to the incident from the beginning, sneaking around the house and peering through windows rather than knocking on the front door and announcing themselves — and asking if everyone is OK. Remember, a neighbor called police out of concern. Instead, Mr. Dean made a four-second, very bad judgment call and shot Atatiana Jefferson to death.

We can’t help but wonder if the same compassionless approach would have been deployed in a white neighborhood, or if an implicit bias that often causes police officers to automatically look at African Americans as a threat came into play.

Too often African Americans aren’t given the benefit of the doubt by police officers, who make unfounded associations about groups of people. For African Americans, it is that they are dangerous and on the wrong side of the law. There are too many stories about African American victims who find themselves treated like the suspect. Like when Harvard Professor Henry Louis Gates, Jr. was questioned by Cambridge police several years ago about whether he lived at his residence, even after showing them identification.

It’s this implicit bias that looks at the misdeeds of young black boys as devious and criminal and those of white boys as childhood mistakes and learning experiences. It’s why the officer who killed Tamir Rice in Ohio didn’t see a young boy playing in the park, but rather an older, potentially violent shooter. This image of black boys as troublemakers is shaped as early as preschool when teachers look at the behavior of children differently depending on their race, a study at Yale University found. It could explain why the black boys are suspended more often than their white classmates.

Growing research has also found that biased judgement and perceptions could also be why in the United States, African Americans are 2.5 times more likely to be killed by police than white people; 1 in 1,000 black boys will be killed by law enforcement in their lifetime.

Police officers across the country need better training on how the unconscious beliefs they have about certain groups of people affect how they respond to crime scenes and 911 calls. It’s clear too many aren’t getting the message as the killings of African Americans by police keep occurring. Thank goodness for cellphone video and social media outrage for keeping the issue in the spotlight, but we’ve reached far beyond the point of outrage and need to come up with solutions.

Some police departments are making it a priority. The Bel Air Police Department for one used a $1,500 grant from The Local Government Insurance Trust this summer to train its officers on recognizing their own biases. The Baltimore Police Department was also ordered by the U.S. Justice Department to train officers as part of a consent decree that took the city to task for brutal policing practices that violated the civil rights of African Americans mainly in West Baltimore. That doesn’t discount that there are also overt racists among our rank-and-file officers. But it can be just as dangerous when officers don’t recognize that their beliefs influence how they do their jobs.

What we do know is that we don’t want to see anymore deaths like that of Ms. Jefferson. At least this time the officer involved is being held accountable for his actions. The police are supposed to protect the public, and it’s about time they realize the public means people of all races.