Chicago officer who fatally shot man under investigation for road rage incident

A Chicago police officer who fatally shot a man in March is being investigated for allegedly pulling a gun on a man during a road rage incident, sources said.

An altercation between an officer and another driver occurred on May 21 in Chicago's Logan Square neighborhood and was caught on bystander cellphone video that was obtained by ABC News Chicago station WLS-TV. The Chicago Police Department told ABC News the incident is under an Internal Affairs investigation but did not identify the officer involved.

Multiple sources told ABC News that the police officer involved was Officer Evan Solano.

Video of the incident shows a man who appears to be Solano in a police uniform holding a gun in his hand arguing with another man standing several feet away.

Solano's attorney, Timothy Grace, did not return email, phone and text messages from ABC News on Sunday requesting comment. The president of the Chicago police union, the Fraternal Order of Police, did not respond to an email from ABC News on Sunday.

Solano, who has been with the Chicago Police Department since 2015, is under a Civilian Office of Police Accountability investigation for fatally shooting Anthony Alvarez, 22, on March 31.

In April, COPA released police body camera footage of the incident showing Alvarez fleeing when officers approached him and a foot pursuit ensuing. In the released footage, Alvarez is seen running away from officers with what appears to be a weapon in his hand. According to the Tactical Response report by CPD, a firearm was recovered from the scene.

A COPA report identified Solano as the officer who shot Alvarez. The agency said in an April 28 release that the officer who discharged his weapon should be relieved of police powers during the pending investigation. However, CPD has not commented or made a decision on that recommendation.

John Catanzara, president of the Chicago Fraternal Order of Police, slammed the COPA report and voiced support for Solano. "The rules of engagement are clear and this officer followed them," the police union president said in a statement on the day the COPA report was released.

"We're hoping that with this video that they came out and everything that happened with Anthony, this man (Solano) finally gets arrested," Alvarez's cousin, Roxana Figueroa, told ABC News.

The Chicago Police Department announced a new policy last week on police foot chases following the fatal shootings of Alvarez and 13-year-old Adam Toledo.

Toledo was shot and killed by a police officer in Chicago's Little Village neighborhood just after 3 a.m. on March 29. Body camera footage shows an officer chasing Toledo down an alleyway. The boy stopped at an opening in the fence and appeared to drop a gun behind it as the officer yelled, "Hands -- show me your f---ing hands. Drop it!" The teenager put his hands up, and then the officer fatally shot him, the video shows.

The COPA investigation of Toledo's shooting is ongoing.

Under the police department's new interim policy, a foot pursuit is only considered appropriate if there is probable cause for an arrest, or if an individual has committed, is committing, or is about to commit a crime or endanger the public, Chicago Police Superintendent David Brown said at a news conference. Foot pursuits are prohibited for minor traffic offenses, Brown said.

"Because foot pursuits are one of the most dangerous actions that police officers can engage in," Chicago Mayor Lori Lightfoot said in a statement, "we cannot afford to wait any longer to put a policy in place that regulates them."

ABC News' Josh Margolin contributed to this report.