(CNN) An officer involved in the 2009 fatal shooting of Oscar Grant at the Fruitvale train station in Oakland, California, was responsible for instigating the events and escalating tensions in the encounter that preceded Grant's death, according to a newly released report.
The 10-year-old report -- recently released thanks to a new California police transparency law -- says that Bay Area Rapid Transit Officer Anthony Pirone "started a cascade of events that ultimately led to the shooting of Grant," and that he then lied about those events in an effort to put his own "actions and conduct in a more favorable light."
Pirone hit Grant and used profanity and the N-word during the incident, the report says, and later lied to investigators about Grant's actions, claiming he hit Pirone's partner and kicked Pirone in the groin.
But Pirone's account was directly contradicted by video evidence reviewed by investigators, the report says.
The report was written by a third-party law firm that was hired to conduct an internal affairs investigation that "examined and analyzed the conduct and performance" of the officers involved in the shooting death of Grant, a black 22-year-old father.
The New Year's Day 2009 shooting was captured on cellphone footage and prompted outrage and protests. It was also the basis for the 2013 movie "Fruitvale Station."
A jury found Johannes Mehserle, the officer who shot Grant, guilty of involuntary manslaughter in July 2010. The report also found evidence that contradicted Mehserle's claim at trial that he had intended to draw and fire his Taser at Grant, and not his gun.
But according to investigators, it was Pirone who, through his words and use of force, was "responsible for setting the events in motion that created a chaotic and tense situation on the platform, setting the stage, even if inadvertent, for the shooting of Oscar Grant."
Investigators ultimately suggested that Pirone be fired for his actions. BART spokesman James Allison confirmed in a statement to CNN that Pirone was "terminated soon after the investigation was finalized."
Pirone declined to comment when reached by CNN Saturday.
The report includes the interviews of numerous witnesses and multiple police officers, including Pirone.
Mehserle did not cooperate with the internal investigation and as a result was not interviewed, the report says.
Early in the morning on January 1, 2009, Pirone and his partner went to the Fruitvale station in response to reports of a fight on the train. Several men were taken off the train and lined up against a wall. Pirone then saw Grant walking between the train cars and used profanity to order him to get off the train.
Pirone told investigators he soon saw Grant "attacking" his partner. Pirone said he approached and Grant attempted to punch and kick him in the groin, to which Pirone thought "I've got a fight now." Pirone said he felt "like I'm fighting for my life at this point."
The report says none of this happened in the footage seen by investigators. They determined that Grant "did not appear to assault" Pirone's partner, and that Pirone grabbed Grant and pushed him against the wall before punching him in the head. "There is no indication that Grant kneed Pirone in the groin as he claims."
Later, Pirone forced Grant to sit back down before hitting Grant in the face with his left knee in an "unprovoked" attack. The autopsy would later suggest "the possible conclusion" that injuries Grant suffered to the face were due to the actions of Pirone, whose use of force, investigators wrote, "did not appear reasonable, justifiable or excusable."
Pirone admitted to using the N-word during the encounter, but said it was in response to Grant directing the word at the BART officer.
Regardless, investigators concluded, Pirone's repeated use of profanity and the N-word served only to escalate the already fraught tensions on the station platform. His use of the N-word "cannot, and should not, be excused, justified or go unpunished," the report says.
Investigators ultimately called for Pirone to be fired because of his unwarranted use of force against Grant, his inappropriate use of language and untruthfulness about his own actions, among other policy violations.
Grant's mother, Wanda Johnson, told CNN in an interview Saturday that it was clear based on the report that Pirone had "instigated the whole situation." Johnson said she'd wanted charges brought against Pirone since the beginning.
"He was just as at fault as the other officer," she said, referring to Mehserle. "He set the stage."
"It's important to know that as a community, as a country, we have to look at our laws and we have to really work to reform our police departments and our judicial system where there is accountability," she said, "and that officers are held accountable when necessary for their actions," she said.