Police say a man groped a woman in Occidental Park sometime around 9:30 a.m. A nearby crowd of people saw or heard about the groping and confronted the man, who then took off running.
The angry crowd gave chase. When caught, the accused grouper allegedly punched two people in the crowd.
Police were called about a fight in the park at about 9:40 a.m., and when officers arrived on scene they say the crowd "wanted to take matters into their own hands."
Officers broke up the melee and arrested the man.
He was booked into King County Jail on suspicion of three counts of assault.