The runner, who did not want his name used, got involved when he heard an 83-year-old woman screaming that her bag had been stolen, the Irish Examiner reported. The woman had just come out of a restaurant Wednesday evening when she was knocked down by the mugger, who grabbed her bag and took off.
The pursuer, from Glanmire just outside Cork, was in the city to celebrate his 24th birthday. He kept up the chase while calling, without result, for people ahead to try to stop the man he was following.
Police said the suspect finally realized he was not going to be able to shake off the chase and started tossing items into the river. He was arrested and charged.
The suspect is described as being in his 20s.
While the man who gave chase was modest, saying anyone else could have done the same thing, a friend said he thought it was a bit more.
"He didn't hesitate and he was in training for the Cork City Marathon so he was always going to keep up with the man who stole the handbag," the friend said.
Police said the mugging victim was shaken by her experience but had no injuries.