2G

Did anything about Terry’s background help ascertain any connections to Shaun, or a reason for the murders?

They both were arrested three times for disorderly conduct such as bar fighting. This may be the reason they were killed.

They were both arrested but there's no evidence they ever met each other. I think they brushed up, somehow, with the killer. Terry's son hates him and it almost sounds like it stems from his mother's death. Shaun did something terrible in his past even though we don't know what it was.

They seemed to be somewhat "birds of a feather" but a long way from murder. The son does hate him, but I don't think he cared enough to have killed him.

Bar brawls seem to be a recurring theme. I’m tending towards someone close to the killer (or maybe even the killer himself) being hurt/maimed in a bar fight?

Low level run ins with the police seems to be common. I’m struggling to think this is connected to the murders.