A student armed with a bow and arrow shot and killed a teacher today at his secondary school in Barcelona, and wounded other three people. 

According to the Guardian, the 13-year-old boy arrived at school late, and when his teacher opened the door to let him in, he aimed and shot the crossbow at her face. At that point, the student started attacking a girl in the classroom, who is believed to be the teacher's daughter.

A substitute teacher who had been at the school just over a week heard the cries and ran to the classroom to help. When he tried to protect the boy's teacher, the teenage boy fatally shot him. 

Witnesses said that before the police arrived, the boy also threatened another student with a knife, and was seen in the hallway preparing a bomb. The student had threatened to attack the school before, and today was heard saying, "I hear voices, I want to stop all the voices."

The Barcelona mayor appeared on the secondary school's campus, and has said he's "appalled" by today's events. It's unclear if the boy will face charges — the age of criminal responsibility in Spain is 18 years old, but there have been cases when younger people have been charged for their actions.

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