Confirming suspicions that have swirled since his arrest for the murder of 17-year-old Chelsea King, John Gardner admitted yesterday to killing both King and 14-year-old Amber Dubois almost a year earlier. The San Diego district attorney won't seek the death penalty against Gardner, reports NBC San Diego, who had guided authorities to the skeletal remains of Dubois after his arrest on condition that that could not be used against him. Gardner, a 31-year-old convicted sex offender, will likely serve two life sentences, plus additional time for other offenses. (More John Gardner stories.)