NEW : Memphis ' police chief says the suspect carried `` a grudge all summer '' and was looking for an excuse to kill again. The city 's police chief said authorities have no indication Marmolejo conspired with anyone , either in the planning or in the execution of the alleged crime . The head of Memphis Junior Academy was found lying in a pool of blood . The teenager is held without bond after a juvenile court hearing , a probation official says .
NEW : Memphis ' police chief says the suspect carried `` a grudge all summer '' and was looking for an excuse to kill again. The head of Memphis Junior Academy was found lying in a pool of blood . The teenager is held without bond after a juvenile court hearing , a probation official says .