The caller could have been pissed cause the cops were giving DW all the GLORY in the MEDIA (tv, papers, etc) and not himself. Criminals most enjoy the fact that they are SMART ENOUGH to ELUDE police. They don't like it when they are successful because the cops made a mistake.
At least the kind of psycho killers that would RAPE, MURDER a young girl, then leave some kind of CALLING CARD.
Danielle's callling card may have been 'disturbed' by 1 extra DAY of animal activity.
See he thought they would find her the first day he called. BUT THEY DIDN'T.
So he had to call back. By that time the animals had eaten parts and drug parts all over the place. RUINED the CALLING CARD effect.