A man whose punch led to the death of a 76-year-old Vietnam war veteran at a St. Paul park has pleaded guilty to manslaughter.

Wyatt Daniel Doerfler, 18, of Rosemount pleaded guilty to first-degree manslaughter Thursday in the death of Thomas Dunne. Because Doerfler was 17 at the time of the assault, Ramsey County Judge Jacob Kraus accepted the plea under extended juvenile jurisdiction, meaning that an 86-month adult sentence is suspended and Doerfler will stay on supervised probation until he turns 21.

Because Doerfler lives in Rosemount, the case goes to Dakota County District Court for a June 18 sentencing to determine his disposition, and whether he will receive electronic home monitoring or time in a juvenile facility.

Investigators say Doerfler punched Dunne the evening of Jan. 28. Officers met Dunne at Harriet Island Park by about 5 p.m. that day. Blood flowed from his right eye. Dunne told officers that he was in the park when he saw a man urinate in public. The 76-year-old took out his phone to take a picture, but two people exited a nearby car and tried taking Dunne's phone away. Dunne said one of the men punched him, and a witness said the men slapped Dunne's phone from his hands before punching him in the face twice.

Police found Doerfler with a group of others later that day. He declined to give a statement but answered, "Yeah, that was me," when officers asked if someone from his group was involved in a fight. A member of the group told officers that they urinated in public because the could not find a restroom. Another member of the group said they thought Dunne was recording him, adding that Dunne should have "minded his business."

Dunne was evaluated at Regions Hospital the day of the injury. Staff discharged him after emergency surgery, but Dunne returned days later with an infection that worsened his condition. Staff placed Dunne on a ventilator, but he was pronounced dead Feb. 23. An autopsy by the Ramsey County Medical Examiner ruled Dunne's cause of death was likely complications from his assault.

Dunne's obituary remembers Dunne as, "a wonderful chef, prolific writer, playwright, acted in amateur theater, licensed pilot, active in his community as a Board member of his Condominium Association and in that role he campaigned for security cameras in Skywalk public spaces."

Dunne's family immigrated to the U.S. from Ireland when he was at 2. He worked at the Chicago Tribune as a teen before enlisting in the Marine Corps in 1966. He served two tours in Vietnam and joined the Army National Guard in retirement. His military service totaled 28 years and includes more than a dozen medals recognizing his career.