Karl Demetrius , 29 , Donovan Demetrius , also 29 , Jaydene Parsons , 23 , and James Ireland , 23 , accused of assisting an offender in murder case . The three men were arrested on Friday after a joint investigation by the FBI and local law enforcement agencies that began last week when they allegedly tried to sell drugs from their car at a Walmart parking lot Nathan Matthews , 28 , has been charged with murder of missing teenager . Shauna Hoare , 21 , charged with attempting to pervert course of justice .
Karl Demetrius , 29 , Donovan Demetrius , also 29 , Jaydene Parsons , 23 , and James Ireland , 23 , accused of assisting an offender in murder case . Becky vanished in Bristol on February 19 and body parts found on Monday . Nathan Matthews , 28 , has been charged with murder of missing teenager . Shauna Hoare , 21 , charged with attempting to pervert course of justice .