Police in suburban Dallas fired an officer Tuesday who reportedly shot and killed a 15-year-old riding in a vehicle leaving a chaotic house party, reports the Associated Press .

The Balch Springs, TX, officer, identified as Roy Oliver, was terminated for violating department policies in the shooting death of Jordan Edwards, police chief Jonathan Haber said.

Edwards, a high school freshman, was leaving the party with his two brothers and two other teenagers Saturday night. Police arrived at the scene to investigate an underage drinking complaint and spotted the vehicle leaving.

Police originally said the teenagers' vehicle was reversing "in an aggressive manner" toward officers, but Haber said Monday that video taken at the scene proved the vehicle was actually driving away.

The police department's latest statement, released Tuesday night, says officers entering the house heard gunshots ring out during a "chaotic scene with numerous people running away from the location." As officers exited the house, they encountered the vehicle backing out onto a main road and driving away despite their attempts to tell the driver to stop, the new statement said.