I thought that Ellie's husband was from Cardiff. It would explain his Welsh accent. Whitby was only connected to Jack so far, I think it is a red herring though as he was 5 miles away from a previous murder, 15 years ago. It is a pretty big coincidence.
I still think Susan Wright's key log book should be checked for authorised access to the cliff top cottage where the murder took place. It may not be so important after what she whispered in the news editor's ear though. That was chilling. PQ does nasty/ sinister really well, does anyone else remember The Sculptress?
The plumber's mate is involved in something dodgy (crossbow in back of van) but that may be theft or an unhealthy interest in killing animals, as another red herring.
Why wasn't anyone checking up on Danny's mobile records? As Jack burnt photos of Danny he thought could be misconstrued as showing an unhealthy interest in the boy, surely he would have burnt or destroyed the phone rather than handing it in. How long would a boy lose track of his phone for though?
Who thinks that Danny and Ellie's son have been on unsavoury Internet chat rooms? Or have they been doing some sort of complicated computer thing, that required a load of files to be deleted. Will the vicar be involved in that? Or is it too obvious?
I'm admiring Alec Hardy's glossy hair though. I wonder what shampoo he uses 