Police do not prevent crimes. For the most part, they only respond to incidents after the fact. However, their investigations rarely produce results or convictions. Often, instead of preventing crime, police officers themselves act as the source of harm and violence.
While the lack of reporting standards makes it difficult to track use of force by police, we know of at least 5,000 fatal shootings by police since 2015. Furthermore, police violence disproportionately impacts Black individuals, who are not only 3 times more likely than white people to be killed by police (despite being 1.3 times more likely to be unarmed), but are nearly 4 times as likely to be subject to use of force by police.