(Portland, OR)  --  A convicted sex offender is pleading not guilty to kidnapping, torturing and murdering an 89-year-old Portland woman.  Timothy Mackley entered the plea in court yesterday after undergoing a mental health evaluation.  Police arrested Mackley September 25 after discovering the body of Marcine Herinck inside his car during a traffic stop.  Investigators believe Mackley followed Herinck home from the thrift store where she volunteered her time.