The father of a 19-year-old man who was fatally shot by Chicago police last year is suing the city and its police department over his son’s death.

The lawsuit, filed Thursday in Cook County Circuit Court, alleges that Chicago police officer Jesse Oeinck was not justified in shooting Juan Flores, who backed his SUV into Oeinck on Sept. 10, 2017, in the Northwest Side Hanson Park neighborhood. It also accuses the police department and the city of failing to investigate an officer’s use of deadly force.

Officers pulled over Flores at 12:19 a.m. as he drove his sports-utility vehicle erratically in the 2100 block of North Laramie, according to police. After officers exited their squad car, Flores pinned one of them with his SUV.

The entrapped officer, Oeinck, fired multiple shots at Flores, who died on the scene from his wounds, according to police and the Cook County medical examiner’s office. Oeinck was taken to a hospital with serious injuries.

The lawsuit alleges that Flores called 911 earlier because his girlfriend’s father was armed and punched him in the face. Officers Clarence McCoy and Charles O’Connor arrived at an address in the 900 block of North Kedvale Avenue and found Flores in his vehicle, saying someone took his car keys.

As the officers and Flores searched the yard, Flores’ girlfriend’s father told them that Flores was drunk and should not be driving, according to the suit.

Someone found and brought the keys to McCoy, who instructed the person to place them on the ground, according to the suit. Then he allegedly walked Flores to his car and let him leave.

“They had just directed an intoxicated, fearful teenager to pick up his car keys, escorted him out to the car and watched him drive away,” the suit said.

Officers Richard Vitellaro and Oeinck noticed Flores driving without his headlights on during their vehicle patrol, so they chased him into a dead-end lot, the lawsuit said. That’s when Flores backed up and was shot and killed by Oeinck. Flores was unarmed.

Chicago police declined to comment on pending litigation Friday, and the city did not immediately return a request for comment.

In November, the Civilian Office of Police Accountability dumped a cache of documents, including dash-cam video, showing Flores backing his SUV into Oeinck. According to police records, Flores called 911 because he believed someone took his car keys.

The footage shows Flores speeding away as an officer yelled at him to stop. Oeinck can later be seen crushed against the hood of a police cruiser as Flores starts backing his SUV into him.

Oeinck fired five rounds before resting his weapon on the cruiser’s hood and falling to the ground, according to police records and the video.

The four-count, 10-page lawsuit accuses police of wrongfully killing Flores and the city for having a “transparent conflict of interest” when it comes to keeping police accountable.

The father seeks monetary damages for his son’s death as well as punitive damages to “deter future misconduct” of officers, according to the lawsuit.