The Trailer Park

Tom's hand is a character metaphor thing. At the beginning his hand is wounded from "An Accident" with no more information, so the audience is meant to find him and his motives suspicious and untrustworthy, and possibly think he may even be the killer. A the end his hand is again wounded and treated which sheds the skin like the title reptile representing the idea that he has changed and left behind the issues of the past i.e. his inaction toward the police corruption in his past. We are also supposed to be suspicious of his constant spending on luxuries that ought to be beyond his means and, even if we don't suspect him of the crime, we are meant to think he may turn a blind eye again and allow the crime to go unpunished. 

The information on the USB drive that Eli gives to Tom provides evidence of the property/drugs scam that the husband, his mother, and the other cops are involved in. The dead wife found out about the scam and was going to expose it which is why she was killed. The guy is arrested based on that evidence. It isn't explicitly stated which one of them killed her but the husband was involved, My own interpretation is that Wally was the killer and his bulldog logo slogan thing could be related to the bites on her hands.

The second time we see the scene of her being found it is in a dream that Tom is having.

I certainly suspected that kitchen accident. If I had cut myself, I wouldn't just tell people it was a kitchen accident - I'd tell them how I almost cut the finger clean off, how I got blood all over the food and... well ok, maybe not quite so much detail. It was still sus.
And I totally missed the bit about Tom dreaming about the dead woman... I mean, I did see the actual dream, but Merlin was distracting me a bit right about then, so I never realised it was a dream. And they really did make it seem like that thing being peeled off his hand was what got the husband in jail (I knew they knew what he'd done but I figured it had to do with the bitemarks on her hands... Like Val would almost certainly agree, there were way too many hands involved