NEW : Would-be parents tell HLN they volunteered for polygraph tests . Gabriel Johnson , 8 months old , has n't been seen since December 26 . Child 's mother was arrested in Miami and is in police custody but wo n't say where he is . Score: 6
NEW : Would-be parents tell HLN they volunteered for polygraph tests . Gabriel Johnson , 8 months old , has n't been seen since December 26 . Child 's mother was arrested in Miami and is in police custody but wo n't say where he is . Police believe they Arizona couple know more than they 're saying .