Protesters in Arizona are demanding justice for an unarmed black man who was shot dead by a white police officer, who mistook a pill bottle for a handgun.

About 100 protesters marched to police headquarters on Thursday night calling for Phoenix police to release the identity of the 30-year-old officer who fatally shot Rumain Brisbon, a 34-year-old father of four on Tuesday, reports NBC News.

Police say that the officer fired two shots at Brisbon during an altercation Tuesday night while they were investigating a drug deal. However, witnesses, including a friend of Brisbon, say that the father was on his way to deliver fast food to his children.

The shooting gives "the impression it's open season for killing black men," said Ann Hart, the chairwoman of the African American Police Advisory Board for South Phoenix, told KPNX-TV.

"We need to look into that," she continued. "We need to take a deeper dive into why police officers are feeling compelled to shoot and kill as opposed to apprehend and detain, arrest and jail."

In response to the shooting, Phoenix police have strongly defended the cop.

"This one went bad from the standpoint of how it ended, but the officer was doing exactly what we want him to do," Sgt. Trent Crump, said Phoenix police spokesman, at a news conference Wednesday.

According to police, Brisbon was approached by cops who told him several times to put his hands up, but Brisbon fled. During a scuffle, the seven-year veteran cop said Brisbon reached for a pill bottle in his waistband, which the officer thought was a firearm.

"The officer gave the suspect several commands to get on the ground but he refused to comply, yelling profanities at the officer," the Police Department said in a statement. "Fearing Brisbon had a gun in his pocket the officer fired two rounds striking Brisbon in the torso."

Police later discovered that Brisbon was carrying a vial of oxycodone pills, and that a semi-automatic handgun and marijuana were in his SUV.

However, one witness told The Arizona Republic that after the shooting, he saw the officer "screaming, 'F--k, f--k, like upset that he shot the guy.'"

Another witness said he did not see the officers trying to speak with Brisbon before the altercation.

Aiyana Raines, 9, said that she cried when she heard the news that her father had been killed.

"He is going to miss our birthdays and how my little sisters grow up, and how we grow up because she is the only one and I am only nine, and my sister is only 10, and my dad is not going to be here for our happy moments and our sad moments," she lamented to Fox 10.