An appeals court Thursday upheld a man’s conviction for shooting at another driver, despite claims the attack was triggered by post-traumatic stress disorder from the Iraq War.

The 1st District Appellate Court affirmed a lower court decision that PTSD was not primarily responsible for the incident and that the veteran was not simply acting in self-defense.

The trial judge in the case ruled there was no doubt Wendell S. Frazier, a former convoy rear gunner who served two tours in Iraq, suffered from PTSD. But he declined to allow a psychiatrist to opine on whether the illness is what caused him to fire shots at another car en route to Calumet City.

The court also ruled there was enough evidence that Frazier provoked the incident.

“The court found that defendant’s actions were not consistent with his PTSD, that defendant was the initial aggressor and that defendant did not subjectively believe that he needed to use force to protect himself from an imminent threat of force,” Justice Eileen O’Neill Burke wrote in the 19-page opinion.

“Accordingly, the court found that defendant’s self-defense claim must fail. We find no basis to disturb that ruling and accordingly affirm the judgment of the trial court.”

Frazier was charged with attempted first-degree murder, aggravated discharge and unlawful use of a weapon after firing multiple gun shots at a vehicle driven by Ryan McGhee in June 2012.

McGhee testified Frazier honked at him while he was texting at a stoplight, then passed him and “brake-checked” him repeatedly while driving on Michigan City Road. McGhee yelled at him through his window.

Frazier testified that when the two came to Pulaski Road, he thought McGhee might be reaching for a gun, so he pulled out a pistol and fired several shots at his car, then drove away. He turned himself into police the next day.

At trial he testified at-length about his military service. He had been responsible for protecting a convoy as a rear gunner and was trained to detect and shoot out enemy vehicles that got close. He also testified that about two weeks before the incident, his own vehicle was hit by random gunfire and that episode caused him to carry a gun.

A Veterans Administration psychologist testified Frazier had symptoms of PTSD and that vehicles were a “huge stressor” for him. His retained expert, a psychiatrist and expert in diagnosing PTSD, had a similar opinion and went further in saying his decision to carry a gun as well as the events of June 2012 were consistent and expected given his mental state. She also opined that the road incident left him in a dissociative state.

Former Cook County circuit judge Allen F. Murphy determined the issue was whether Frazier’s PTSD prevented him from having criminal intent or caused him to believe he needed to act in self-defense.

He found the actions were not consistent with PTSD. He armed himself because of the incident two weeks beforehand, not because he was “reliving events” of military service, Murphy stated.

And if Frazier’s job in the service was to keep vehicles away, there was no good reason to pass the other driver and repeatedly slam on the brakes, drawing him closer, Murphy noted.

He also noted Frazier didn’t say anything to authorities about reliving a combat situation after he turned himself in; that the first thing he did after the episode was give the gun to his mother, evincing a level of guilt.

His proficiency with firearms, along with the damage to McGhee’s car being localized toward the front and tires, suggested Frazier didn’t intend to kill, so the attempted murder charge was unsupported.

However, he found the state proved he was guilty of aggravated discharge. He was sentenced to two years of probation.

Frazier appealed, arguing the judge erred by not letting the psychiatrist testify his PTSD caused him to arm himself and fire the gun, that he incorrectly substituted his own opinion over the expert’s as to the effects of PTSD and that the court failed to consider evidence that Frazier believed he was in danger.

The judge did prohibit the psychiatrist from explaining whether PTSD specifically “caused” Frazier to arm himself and shoot at McGhee, the appeals court noted Thursday, because she was not with him at the time of the incident and his state of mind was outside her expertise.

That “ultimate issue” of a mental state at the time of the crime is a question for the trier of fact to determine.

Frazier framed his case as one of self-defense, that he was justified in carrying and firing the weapon. But the fact he also put PTSD at the heart of it made it seem more like a “diminished capacity” case, Burke wrote. That’s where a technically sane defendant presents evidence of mental illness to negate the intent necessary to commit a crime.

The problem, the court wrote, is that affirmative defense is not recognized under Illinois law. Frazier’s constitutional right to present a defense was not violated either, the panel wrote, because multiple experts testified extensively about his military service and PTSD, and he did the same.

In essence, “defendant’s defense failed not because his or his expert’s testimony was improperly limited but because he failed to sufficiently establish a legally recognizable defense to the charged offense,” Burke wrote. “As such, we find that the trial court did not abuse its discretion in limiting [the psychiatrist’s] testimony.”

The ruling that Frazier acted in self-defense was also not incorrect, the court wrote, because it was clear from the evidence that he was the initial aggressor in the situation.

“In essence, the question before the trial court was whose version of the events was more credible. Defendant attempts to frame the issue as whether or not his PTSD ‘caused’ him to arm himself and shoot at McGhee; however, this again resembles a diminished capacity defense, which is not recognized in Illinois,” the panel concluded. “Essentially, the court credited McGhee’s testimony that defendant was the initial aggressor and that McGhee was unarmed.”

Michael A. Scodro, of Mayer Brown LLP, represented Frazier in the case. He said this morning that PTSD “presents complex issues for the criminal justice system, and we’re reviewing the opinion and considering any further options.”

The Cook County State’s Attorney’s Office represented the state in the case. A spokeswoman for the office also could not be reached.