A San Jose police officer who was fired last year after sending what some called racists tweets is back on the force.

Sources tell NBC Bay Area an arbitrator ruled the tweets, which were about the Black Lives Matter movement, were not cause to fire Phillip White.

"This is just utter outrage," said Raj Jayedev of the watchdog group Silicon Valley Debug. The group led the fight to get White fired.

White's tweets led to protests in San Jose, demanding that he be fired. One of the officer's tweets read: "Threaten me or my family and I will use my God given and law appointed right and duty to kill you #COPSLIVESMATTER."

Another tweet read: "By the way, if anyone feels they can't breathe or their lives matter, I'll be at the movies tonight, off duty, carrying my gun."

Jayedev was shocked to hear White is back on patrol for the San Jose Police Department.

"This person that essentially commits hate crimes and offers death threats on social media, that he would be allowed to be an officer again just shows how broken the arbitration system is," Jayedev said.

San Jose Police Officers Association President Paul Kelly released the following statement regarding White's return: "The personnel process has reinstated Officer White and it is our hope that the offensive social media comments that were the center of this personnel action are never repeated."

White is a 20-year veteran officer. Prior to be being fired, he ran a gang intervention program for kids.

Acting Chief Eddie Garcia called an emergency meeting of his community advisory board on Thursday afternoon to inform members White is back on the force.

Garcia released the following statement:

"Pursuant to state law, all police officers who have successfully completed probation are entitled the opportunity to participate in an administrative appeal of any discipline imposed by their employer.

"An employee challenging formal discipline, including dismissal, may participate in binding arbitration and have an arbitrator determine whether there is just cause for the discipline imposed by the City. While the City and Department disagree with the Arbitrator’s conclusion, we respect the process and will move forward with reinstatement.

"The Department recognizes that the individual character and excellence of each Department member reflects upon the Department. Therefore the Department will continue to expect each of its members to maintain a high ethical standard and provide equitable treatment for all its citizens."