By Dana Feldman SANTA BARBARA, California (Reuters) - With a California town grieving the deaths of six college students killed by a mentally ill man, one victim’s father on Monday blamed the killings on politicians who failed to tighten gun laws after a mass school shooting in Newtown, Connecticut. Richard Martinez, whose son Christopher Michael-Martinez, 20, was gunned down on Friday night in Isla Vista, California, said similar rampages would continue until lawmakers took action on guns. “I can’t tell you how angry I am. It’s just awful, and no parent should have to go through this.” Elliot Rodger, 22, the son of a Hollywood director, fatally stabbed three people in his apartment before shooting three people dead near the University of California at Santa Barbara. Martinez said his son died because Congress had failed to act after a mentally ill gunman killed 26 people in December 2012 at Sandy Hook Elementary School in Newtown, Connecticut.