The Evidence Against Lockhart.

1. He's already admitted to being close to the cabin.

2. His muddy shoes gave him away.

3. He's got a past with the dead man too.

4. Things weren't always smooth between them back in their hometown.

5. And revenge is a dish best served cold. Or even shattered.

(SOLUTION FOLLOWS)

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6. The muddy footprints prove he had opportunity. The elephant shard with Bingham on it is an apt symbol of his broken friendship with the victim.