Police probe motives behind fatal San Bernardino classroom shooting

Relatives of a school teacher shot dead by her husband in a San Bernardino, California, classroom have told investigators the slaying capped a brief, turbulent marriage and breakup marked by accusations of infidelity and threats, police said on Tuesday.Police also revealed that surveillance video showed the shooter initially had tried to get into the school through a locked door, forcing him to gain entry instead by way of the front office, where he signed in and was allowed free access to the c