Christine SchÃ 1\/4 rrer , ( born 30 June 1976 in Hannover ) is a German criminal . On March 17 , 2008 , she murdered two Swedish children and seriously injured their mother after attacking them in their Arboga , Sweden home . Christine SchÃ 1\/4 rrer ( born June 30 , 1976 , in Hanover ) is a German citizen who murdered two Swedish children and seriously injured their mother with 15 blows to the head with a hammer after attacking them in their home in Arboga , Sweden , on March 17 , 2008 .