The last suspect charged in the brutal 2013 beating of Ray Widstrand pleaded guilty Tuesday morning to throwing the first punch, testifying that he attacked for “no reason.”

Charles K. Redding, 17, pleaded guilty in Ramsey County District Court to aiding and abetting first-degree assault in the attack in St. Paul. As part of his plea, two counts of crime committed for the benefit of a gang and one count of aiding and abetting first-degree aggravated robbery will be dismissed.

Redding admitted instigating the Aug. 4 attack by throwing the first punch at Widstrand, who was stepping in the middle of a melee to help a young woman off the ground. Widstrand, who was 26 at the time, was knocked out and pounced on by several more assailants who kicked him, stomped on him and stripped him of his shorts.

Widstrand, now 28, was left unconscious in the street with a skull fracture, so severely injured that authorities and doctors feared that he would die. He has permanent brain damage.

Redding was 15 at the time and certified as an adult in the case. He unsuccessfully appealed the certification.

Widstrand was living in the Payne-Phalen neighborhood of St. Paul’s East Side when he was attacked. A crowd of about 40 teenagers had spilled out of a house party on Preble Street near Minnehaha Avenue to watch girls fight.

Assistant Ramsey County Attorney David Miller asked Redding Tuesday what he did when he saw Widstrand.

“I just punched him,” Redding testified on the witness stand.

Redding said that he punched Widstrand in the face with his bare fist, and that it was a hard strike.

“Why did you strike him?” Miller asked. “What was the purpose of hitting him?”

“No reason,” Redding said, bringing his testimony to a close.

Five of the suspected attackers — authorities say there were more who remain unidentified — were charged. One teen was convicted and sentenced to 16 years in prison, another was acquitted, a juvenile pleaded guilty and one case was dismissed.

“We believe we’ve charged all the individuals we believe we can prove assaulted Ray Widstrand,” Miller said after Redding’s plea.

Neither Widstrand’s nor Redding’s families attended the plea hearing.

Miller said that Widstrand has a restricted driver’s license and is able to drive during the day and has returned to work at a public-access TV station, but is unable to live on his own.

Redding is scheduled to be sentenced on May 1. His attorney, Bethany O’Neill, is expected to argue for a sentence at the low end of the sentencing guidelines for his conviction — about six years — while Miller is expected to argue for the high end — about 8½ years.