A man arrested in a fatal stabbing last weekend outside a West Town bar is a veteran of the U.S. Marine Corps who was convicted of battery three years ago after he pulled a gun on a man in the northwest suburbs and tackled him to the ground, according to court records.

The stabbing happened about 11:20 p.m. Friday down the street from Richard’s Bar at 491 N. Milwaukee Ave., reportedly after a fight between the ex-Marine and Paterimos inside the bar.

The 30-year-old man, who the Chicago Sun-Times is not naming because he has not been charged in connection with the stabbing, was released from police custody Sunday after he claimed he stabbed 23-year-old Kenneth Paterimos in self-defense, officials said. Police said Tuesday their investigation was ongoing.

Authorities and Paterimos’ family said the ex-Marine yelled a racial slur at Paterimos during the fight and the ex-Marine was kicked out. Paterimos left the bar soon after to go home, his family said, and was headed for a nearby Blue Line station when he was repeatedly stabbed.

Paterimos returned to the bar and collapsed, leading his older brother, Santiago Bueno, to rush out the door and tackle the ex-Marine outside the bar, family said. Bueno, who is trained in martial arts, held the man outside for authorities, his family said.

A worker at the bar Wednesday said he didn’t want to talk about the incident.

Court records show the ex-Marine was convicted of battery stemming from an incident in December 2016 in the 2600 block of North Walnut Avenue in Arlington Heights.

Arlington Heights police reported that he was unlawfully carrying a .22-caliber Walther PPK pistol and tried to strike a man with it before taking the man to ground, causing lacerations to the man’s hand and knees.

He pleaded guilty in June 2017 to a count of battery and prosecutors dropped a charge of unlawful use of a weapon, records show. He was sentenced to 18 months probation and ordered to attend counseling.

He did not respond to messages left via email and his cellphone Wednesday seeking comment.

In a letter included in the court file from a social worker at the Road Home Program, a center for veterans and their families at Rush University Medical Center on the Near West Side, a social worker wrote the man had been “diagnosed with PTSD [Post Traumatic Stress Disorder] related to his military experience.”

The man’s LinkedIn account says he served honorably in the Marines from 2008-2013, completing two overseas deployments in support of Operation Enduring Freedom. The account said he was awarded a medal for his actions during combat in Afghanistan.

Military officials could not immediately confirm his service.

His most recent job was listed as a union laborer working for an Arlington Heights asphalt paving company.

Someone who answered the phone at the paving company Wednesday said the ex-Marine had not been employed by the company for several years.

That man, who asked not to be named, described the former employee as a “good kid” who was “smart,” but “had some issues.”

“Just serving [in combat] can give you some issues,” said the man, who declined to elaborate.

Up until about a year ago, the ex-Marine lived in an apartment complex in Old Town, according to court records and people who knew him then.

Other tenants and staff of the complex said they recalled the man as “eccentric” and “a character,” but a “nice dude.”

They said he would often wear a hat that read “Air Marshal” on it — and he told people he was one — but they said they privately doubted it.

Contributing: Jake Wittich