Germany Mourns Victims, Searches for Perpetrator of Berlin Attack

German investigators are looking for the perpetrators of the truck attack on a Berlin Christmas market that killed 12 people on Monday. The police have released a Pakistani national, their only suspect in the attack, saying they did not have enough evidence to charge him with a crime. Islamic State has claimed responsibility for the attack in a statement posted by the group's media outlet Amaq. Zlatica Hoke reports.