The evidence is mounting. The man arrested after killing four people by driving a truck into a crowd of people and into a luxury department store window in Stockholm is from Uzbekistan and was carrying explosives, Swedish media report. The attack in a busy shopping area Friday afternoon also injured 15 people, nine seriously. Authorities said they arrested the terror suspect 25 miles north of the city and are investigating others in the incident involving a carjacked Swedish beer truck. As the investigation continues, Prime Minster Stefan Lofven has tightened border security.