WAUKEGAN, Ill. (NewsNation Now) — Illinois State Police are investigating after a suburban Chicago police officer fatally shot a 19-year-old Black man and wounded a Black woman after her vehicle rolled toward the officer following a traffic stop, authorities said Wednesday.

NewsNation affiliate WGN reported the driver was identified by family as Tafara Williams and is expected to recover. Williams was driving with passenger, Marcellis Stinnette, and the two were a couple, according to family.

The two were in a vehicle that fled a traffic stop late Tuesday, according to Waukegan police. It was spotted a short time later by an officer on patrol. While the officer was approaching the vehicle, it began moving in reverse. Authorities said the officer, fearing for his safety, opened fire. No weapon was found in the vehicle, police added.

Preliminary autopsy results on Stinnette indicate that he died “from injuries due to a gunshot,” Lake County Coroner Dr. Howard Cooper said.

“We have been in close contact with Mr. Stinnette’s family and our deepest condolences go out to them during this difficult time. This is truly a tragedy,” Cooper said in a statement.

Body camera and squad car video has been turned over to Illinois State Police, Waukegan Police Commander Edgar Navarro said. State police will present its findings to the Lake County State’s Attorney’s Office.

Lake County State’s Attorney Michael Nerheim noted in a statement that it may be several weeks before the investigation is completed.

“Once I have had the opportunity to review the entire investigation, I will make a determination regarding whether the officers violated any laws,” Nerheim said. “Should it be determined the officers violated a law, they will be criminally charged.”

The officer who shot the couple is Hispanic and a five-year veteran of the Waukegan department. The officer who conducted the original traffic stop is white, according to the department.

Family members of the wounded woman, including her parents, gathered outside Waukegan police headquarters Wednesday afternoon. The woman’s mother said her daughter and the teenager hadn’t done anything to provoke the shooting and that her account of what happened differed from police.

“I don’t know why they did this to my baby,” Clifftina Johnson, Williams’ mother said to WGN. “I’m not going to get it, but lord knows they need to stop being trigger happy.”

During a Wednesday news conference, Waukegan Mayor Sam Cunningham asked city residents to wait until all the facts are known before reacting to the incident.

A protest was scheduled for noon Thursday at the site of the shooting, followed by a march to police headquarters, said Clyde McLemore, the Lake County chapter president of Black Lives Matters. He called for calm.

“We’re not here to rip up our own town,” McLemore said.

NewsNation affiliate WGN and The Associated Press contributed to this report.