Interstate 55 and Interstate 90 as seen from above the Near South Side on July 26, 2022. Credit: Colin Boyle/Block Club Chicago

MCKINLEY PARK — Illinois State Police are investigating a shooting that left one woman critically injured after an off-duty officer and another person shot at each other the Stevenson Expressway last week — but both sides are disputing who opened fire first.

The shooting occurred around 10 p.m. Aug. 4 on the Stevenson near Ashland Avenue, officials said.

A 22-year-old man and an unidentified off-duty Chicago police officer were driving in the northbound lanes when the officer and people in a blue Nissan Maxima began arguing with each other, according to the Sun-Times, citing what the officer told officials.

At some point, someone inside the Nissan pointed a green laser light at the officer’s vehicle, and that person and the officer shot at each other, according to the Sun-Times. A 24-year-old woman driving the Nissan was shot in the head and taken to Northwestern Memorial Hospital in critical condition, officials said.

State police said investigators recovered a black Glock handgun that was converted to be fully automatic and had a green laser light, according to the Sun-Times.

David C. Abarca, a passenger in the Nissan, was charged with attempted murder, aggravated unlawful use of a weapon and aggravated discharge of a firearm, according to the Cook County State’s Attorney’s Office. He was ordered held without bail Sunday, a spokesperson said.

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It is not clear who shot the woman, and police officials and Abarca’s attorney have blamed the other for instigating the violence.

Police Supt. David Brown told reporters earlier this week Abarca shot at the officer first and the officer, who wasn’t in uniform, returned fire. Abarca’s lawyer told the Sun-Times the officer fired first upon seeing the green laser light pointed at his car, thinking someone was about to shoot at him.

Chicago police’s use of force policy forbids officers from shooting at moving cars.

The Civilian Office of Police Accountability, which investigates use of force from officers, said it was responding to the scene of the off-duty officer-involved shooting in a statement on Twitter last week.

A spokesperson for the agency said it’s an active and ongoing investigation, and there are no updates as of Wednesday afternoon.

The officer involved remains on active duty. Chicago police referred questions to the Illinois State Police. State police said there is no additional information available as of Wednesday afternoon.