The Titanic and the Indifferent Stranger

While the Titanic lay sinking, the lights of a ship were seen nearby, and distress rockets were sent aloft to attract her attention. But the indifferent stranger never responded...and 1500 people died in the frigid North Atlantic waters. Who was the mystery ship? Why did she not respond to this most basic appeal for assistance....after all, everyone seemingly knows what rockets at sea mean...? The blame has been placed on a British steamer, the Californian, and her captain, Stanley Lord, was forever blamed for ignoring a plea for help as he lay sleeping below while his officers impotently watched rockets going up. Is this simplistic view of the case correct? Was Captain Lord guilty of mass murder?