A Chicago man has been arrested for allegedly clobbering a train passenger on the head with a hammer this week, and he is also being investigated in connection with nearly a dozen similar attacks. Curtis Tyler, 30, was taken into custody just after 6am on Tuesday, less than an hour after police said he struck a 50-year-old man on the head while riding the CTA Red Line train in the 1200 block of North Clark Avenue. Tyler was booked into jail on charges of aggravated battery using a deadly weapon, theft and public indecency. He was also issued a citation...