What is important to me are the words Jeremy supposedly used in that conversation, whatever time it was. "Something is wrong at the farm."
If he had killed his family, I see no logic in those words being used. If he didn´t, I do see some logic: his father had just phoned him saying "She/Sheila´s gone mad, she´s got the gun, come quickly." (not verbatim, sorry). It is a confusing message to get in the middle of the night. Jeremy must have thought: Why didn´t he call the police - or did he call the police? Does he want me to call the police - wouldn´t he have told me to call the police? I wonder if I should call the police, maybe he will get mad if I do - he told ME to come over. I am scared to go there if Sheila has gone mad with a gun. What shall I do??? I´ll call Julie, perhaps she can tell me what I should do. RINGRINGRING, Jeremy: "Something is wrong at the farm (he probably said a few more sentences, including maybe, what do you think I should do?)" Julie: "It´s probably nothing, Sheila has fits all the time, go back to bed."
Jeremy alone again, nah, I can´t just go back to bed, dad sounded very upset. I´ll call the local coppers, maybe that will upset dad less than if I call 911.
Makes sense to me.