LAS VEGAS Officers from two Nevada law enforcement agencies opened fire during a pre-dawn chase through Las Vegas as they tried to stop a man who fatally shot his mother, then stole a police cruiser and carjacked bystanders at gunpoint while trying to evade police, authorities said Friday.Advertisement 2 Story continues below This advertisement has not loaded yet, but your article continues below. Article content We apologize, but this video has failed to load. Try refreshing your browser, or