The bloody rampage began at around 9:45 a.m. local time (08:45 GMT) when the 17-year-old gunman entered the Albertville school in Winnenden dressed in black combat fatigues and opened fire on the pupils, the German television channel N-24 said.
Nine students and three teachers as well as a person at a nearby clinic were killed in the attack. The gunman, who has been confirmed as a former student of the school, managed to flee the scene after kidnapping a man and his Volkswagen Sharan car, the channel said.
Police caught up with the attacker some 40 kilometers (25 miles) from Winnenden in a supermarket, where he was killed in a shootout with officers. Two passers-by were also killed and two police officers seriously injured in the exchange of fire, bringing the total death toll including the shooter to 16.
Police said they found 18 weapons that were legally held in the house of the teenager's parents. It is unclear whether he used the weapons during the attack.
