Betty Shelby, the white Oklahoma Cop who in September shot and killed Terrence Crutcher — an unarmed black man — was acquitted of felony manslaughter Wednesday evening.

The case typifies something disturbing about the way our society views black men.

People were not happy and expressed their thoughts on what many were calling an injustice on Twitter:

What happened?

On September 16, 2016, Terrence Crutcher's car stalled in the middle of the roadway, reports HuffPost. Officers, responding to an unrelated call, found Crutcher and ordered him to put his hands up. While the police department originally claimed that Crutcher refused to comply and put up his hands, a video of the incident seems to show otherwise. Crutcher appeared to have his hands above his head, and was walking towards his car, when Officer Betty Shelby shot and killed him.

Shelby's lawyers argued that she believed Crutcher was going towards his car to get a gun, according to NPR.

It was argued that Crutcher disobeyed an order to stop and get on the ground. When he began walking toward his car, the defense argued - Shelby believed Crutcher was going to get a gun. No gun was found on Crutcher or inside his car. Officers did find PCP, a hallucinogenic drug, in the car, and an autopsy later revealed that Crutcher had the drug in his system when he died.

According HuffPost, the jury deliberated for nine hours, but ultimately, they acquitted Shelby. "At least four of the 12 jurors were crying as they left the courtroom and they did not look at either the family of Crutcher or Shelby. The jury comprised eight women and four men and included three African-Americans," according to the Associated Press (AP).

In many of the recent cases involving police shootings of black men, defendants used a similar defense: claiming they feared for their lives.

Officer Darren Wilson used a similar defense in the 2014 shooting of Michael Brown, and a grand jury brought no charges. Officer Michael Slager used the same defense to justify his killing of Walter Scott in 2015, despite the fact that Scott was fleeing when he was killed.

Why does this defense seem to work so well for cops?

It might be because our society views black men as more dangerous — and even physically larger — than their white counterparts, according to a new study. "Unarmed black men are disproportionately more likely to be shot and killed by police, and often these killings are accompanied by explanations that cite the physical size of the person shot,” lead author John Paul Wilson, Ph.D., of Montclair State University, said in a press release. “Our research suggests that these descriptions may reflect stereotypes of black males that do not seem to comport with reality.”

The study also suggests that participants judged black men to be stronger and more muscular than white men of the same size, and even judged the black men more capable of inflicting harm in a hypothetical altercation.

For example, in his grand jury testimony, Wilson described his tussle with Michael Brown this way: "When I grabbed him, the only way I can describe it is I felt like a five-year-old holding onto Hulk Hogan."

But the perception of black men as dangerous individuals isn't really true. In fact, a recent study found that of 990 police shootings in 2015, black victims were less likely to have been attacking police when they were killed than white victims.

The misperception that black men are dangerous or violent can have deadly consequences.

Officers who are more likely to feel endangered by black men are more likely to pull their guns in self-defense. It could help explain why blacks are more than two times more likely to be killed by police than whites.