A 45-year-old man who got in a fight outside a Lake Street restaurant and died from cardiac arrest is now considered the victim of a homicide, and police said Thursday that they are looking for a suspect.

Jimmie Ray G. Herron Jr. of Minneapolis died March 4 at Hennepin County Medical Center, a few hours after getting in a fight outside Denny’s in the 2700 block of E. Lake Street.

The assault on Herron was a complicating factor leading to the cardiac arrest, the medical examiner’s office said.

Herron’s mother, Assata Damani, said Thursday that her son was a “very quiet person … who wasn’t one to start conflicts, but he wasn’t one to back away, either.”

In the moments after the fight, his mother added, Herron called a relative about the incident and said he gotten into a fight with two people.

Police have made mention of only one possible suspect, described by Sgt. William Palmer as a man in his 20s.

According to police:

Shortly before 1 p.m., police were called to a fight outside Denny’s. Herron complained to officers about having heart trouble that followed the fight. His adversary had left the scene, and Herron said he didn’t want police to do anything about the conflict. Police have not said what prompted the fight.

Emergency medical personnel took Herron to HCMC, where he died less than two hours later. Herron had a history of heart disease, the medical examiner’s office said.

A restaurant manager said she does not believe the incident was connected to her business.

Anyone with information regarding the fight is asked to call police at 612-692-TIPS.

Herron was born in South Bend, Ind., and excelled at chess starting at age 4, according to Herron’s death notice, posted online by the Clark-O’Neal Funeral Home of South Bend.

He graduated from St. Mary’s University in Minneapolis with a master’s degree in computer and information technology, the notice continued, and was getting started on a doctorate at the time of his death.

“I talked to him every day up to the day he died,” Herron’s mother said. “My son had been sick with the flu [that day], and it was the first time he had been out of the house in two weeks.”