A shout against violence: Students of Thomazia Montoro public school shout for peace and against violence in front of a banner of Elisabete Tenreiro, a 71-year-old teacher who was stabbed to death Monday, during a vigil at their school in Sao Paulo, Brazil, on Tuesday. A 13-year-old student attacked Tenreiro and wounded three other teachers and two fellow students in a knife attack.