Police said the suspect, 37-year-old Gokmen Tanis, had been taken into custody after an hours-long manhunt and had earlier run-ins with authorities in the Netherlands. The city was put into lockdown after the shooting, shortly after the morning rush hour, which authorities initially said was an apparent terrorist attack. The Turkish intelligence agency said it is investigating whether the attack was personally motivated or an act of terrorism, President Tayyip Erdogan said.