The investigation found that officers Gabriel Jordan and Daniel Greene were justified in shooting Hernandez after a confrontation, District Attorney Mitchell Morrissey said.
On Jan. 26, Hernandez was behind the wheel of a stolen car when it was approached two officers on foot, according to the Denver Police Department.
Authorities said Hernandez drove the car, which had four other teens inside, into one of the officers and struck him on the leg. Both officers then opened fired, hitting Hernandez multiple times. She was taken to a local hospital where she was pronounced dead.
The coroner, who ruled her death a homicide, said that none of the shots were fired at close range.
In a letter Friday to the Denver police chief, Morrissey said it was a "defensive shooting" by both officers.
"Their decisions to shoot Ms. Hernandez were justifiable in light of the manner in which she drove the car in close and dangerous proximity to them, threatening the life of Officer Jordan who had little room to avoid the car," Morrissey said, adding that the force used by the officers was "legally justified."
Attorneys for Hernandez's family said the report showed she was shot from the driver's side of the car, implying that the officers were not in the car's direct patch, therefore contradicting police statements that she was driving at them when they fired.
In a recorded statement hours after the shooting, Jordan, a nine-year veteran of the police department, told investigators he believed the driver was trying to run him over.
Despite yelling to the occupants of the car to get out and put their hands up, Jordan said Hernandez continued to drive "right at me." He told investigators that he was approximately 10 feet away from the Honda when he heard the engine rev loudly and "before I know it, the car's driving right at me at a high rate of speed."
Jordan said that the car came inches of him and he "hit the car" with his hand.
He added that he feared he was going to get pushed up against a fence or a brick wall behind him.
"I'm thinking that any minute I'm going to get pushed up against the background and I'm going to get tumbled through and I'm done. I was thinking I was going to die," he said.
Jordan said he began firing his gun as fast as he could pull the trigger when he thought he was "going to get squished and killed."
His aim was "right at the driver's seat right in front of me." Jordan said he felt lucky to have survived.
Greene said that as soon as he heard Jordan's gun, he fired three shots at the driver as he believed that Jordan was in the path of the stolen car and that "he would have been run over and seriously injured or killed."
Trina Diaz, 16, who was sitting in the passenger seat when the shooting occurred, told BuzzFeed News in February that Hernandez hit the officer only after she was shot and lost control of the car.
"Jessie was clinging to her life after being suffering four gunshot wounds," said Qusair Mohamedbhai, the Hernandez family attorney. "She was then dragged out of the car, dropped onto the ground, and handcuffed. The abrasions to her face confirm this inhumane treatment."