Johnson tried to run, but police chased him, authorities said. He was captured in a parking deck, police said.
Johnson and the injured man know each other, authorities said. The details of what prompted the attack are not clear.
Johnson was booked into the DeKalb County jail late Saturday evening on an aggravated assault charge, jail records show.
In other news:
Witnesses said a person was on a personal watercraft and was trying to pull it onto a boat ramp at Shoal Creek Park when the watercraft flipped over around 8 p.m.