Police on Monday arrested another suspect in the April 1 attack on 83-year-old Charles Clark. Marquez Dunbar, 20, of St. Petersburg, was arrested Monday and charged with armed robbery as well as violating his probation on previous charges of carjacking and resisting arrest with violence, according to Pinellas Park police. Dunbar was released from prison in November after he served a three-year sentence for two counts of carjacking and resisting an officer with violence. Three teens were arrested last week after police said Clark was attacked and stabbed outside his condo. While he recovered from his injuries that night, his car was stolen. It was later found abandoned in St. Petersburg.