DALLAS — Police in suburban Dallas fired the officer Tuesday who shot and killed a black 15-year-old boy who was riding in a vehicle while leaving a house party.

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

The officer fatally shot Edwards, a high school freshman leaving a party with four other teenagers Saturday night. Officers were called to the scene to investigate an underage drinking complaint.

Police originally said the teenagers’ vehicle was reversing “in an aggressive manner” toward officers, but later said that video taken at the scene proved the vehicle was actually driving away. An officer shot his rifle through the front passenger side window and struck Edwards, said Lee Merritt, an attorney for Edwards’ family. The Dallas County medical examiner ruled his death a homicide.

Thousands of Facebook and Twitter users have posted about the case in recent days with the hashtag “(hash)jordanedwards,” some comparing his death to other police shootings of young black men, such as 12-year-old Tamir Rice in Cleveland who was fatally shot in November 2014 as he held a pellet gun.

Friends have described Edwards as a good student and popular athlete. Edwards and the four teenagers with him decided to leave what was becoming an unruly party as they heard gunshots ring out and police were arriving, Merritt said, citing what witnesses had told lawyers.

Two officers arrived at the scene, Haber said on Monday. One of them opened fire at the vehicle as it was moving, killing Edwards. The teenager’s brothers “witnessed firsthand” what happened, Merritt said.

Based on what the video captured, Haber said previously that he questioned whether what he saw was “consistent with the policies and core values” of his department. Haber wouldn’t say what problems he saw, but Balch Springs’ official use-of-force policy encourages officers facing an oncoming vehicle to “attempt to move out of its path, if possible, instead of discharging a firearm at it or any of its occupants.”

The Dallas County district attorney’s office and the Dallas County sheriff’s office are investigating the case.