Marcellis Stinnette, 19, was killed when an officer opened fire on his car.

The police officer who opened fire on an unarmed Black couple in Illinois, killing a 19-year-old and seriously injuring his girlfriend, has been fired.

The Waukegan, Illinois, officer, who has still not been named, was fired late Friday, according to Waukegan Chief of Police Wayne Walles.

“In the evening hours of October 23, 2020 the City of Waukegan terminated the officer that discharged his firearm during that incident, for multiple policy and procedure violations,” Walles said in a statement.

Marcellis Stinnette was killed Tuesday night when an officer opened fire on the vehicle he was a passenger in at about 11:55 p.m., according to police.

Waukegan Police Department Cmdr. Edgar Navarro said earlier this week that Stinnette was sitting in the passenger seat of a “suspicious” car that was approached by an officer. The car fled and was later pulled over by a second officer.

“That officer exited his vehicle and the vehicle that he was investigating began to reverse toward the officer,” Navarro alleged. “The officer then pulled out his duty weapon and fired into the vehicle that was reversing. Both occupants were struck.”

Tafarra Willams, the mother of Stinnette’s child and diver of the vehicle, was struck in the hand and stomach and is still recovering in the hospital. Her injuries were not life-threatening.

Both officers had been placed on administrative duty while the shooting was being investigated.

The investigation is being handled by the Illinois State Police, a fact reiterated by the police chief in his statement Friday night.

“The Illinois State Police are continuing to conduct their independent investigation,” he wrote. “Once that investigation has been completed, it will be turned over to the Lake County Illinois State’s Attorney’s Office for review.”

Prominent civil rights attorneys Ben Crump and Antonio M. Romanucci announced earlier Friday that he would be representing the 20-year-old Williams.

“Ms. Williams’ legal team will begin our own investigation into what happened during that incident, because we do not trust the police narrative in this case. We have seen over and over that the ‘official’ report when police kill Black people is far too often missing or misrepresenting details,” Crump said in a statement. “We will share our findings with the public when we have uncovered the truth.”

Crump and Romanucci also represent the families of George Floyd and Daniel Prude, both killed by police earlier this year.

Waukegan Mayor Sam Cunningham said at a news conference Wednesday he was worried about violent protests in the city.

“I’m nervous because there’s a lot of uncertainty out there, there’s a lot of rumors flying around. I’m nervous for Waukegan,” Cunningham said. “We’ve seen this play out throughout this country. It just rips through communities and it takes years to rebuild.”

Protests have remained relatively small and peaceful in the days since the killing.

ABC News’ Devin Villacis and Will Gretsky contributed to this report.