Police say the acquaintance pulled a folding knife and stabbed the man in the chest. The knife hit the man’s defibrillator, a device that shocks the heart if it gets dangerously out of rhythm. Police say the man was taken to a hospital with serious injuries. His name hasn’t been released. Authorities arrested 60-year-old Richard Kiley at another trolley station on suspicion of attempted murder. He remained jailed.