I must admit I was more interested in the answer machine and the possibility that there could be some evidence contained on one of the five audio tapes, which the police had seized from his cottage in September 1985...
If Jeremy I've been at the Farmhouse and had made the call to himself, that is to his Cottage, the answer phone would have been activated had it been switched on. There would in those circumstances have been an audio recording of the phone call. Unless, of course, had Jeremy been the Killer, and he had intended to rely upon the last number dial facility on the digital phone which was normally plugged in at the kitchen socket! The only other alternative, would be was that with Jeremy at the Farmhouse making the call to his own Cottage at Goldhanger, there was someone else back at his Cottage who lifted the receiver of the telephone there off its cradle as if to answer the call. But, it would have been far easier for him had he been the killer, simply to unplug his home phone and switch off his answer machine before returning to the farmhouse to kill everybody, and leave the digital statesman phone that was normally plugged in at the kitchen socket back at White house farm (with its last number dialled facility), and he simply dial his own number and leave the handset off its cradle!
But...
The round finger dial telephone appears to have been plugged in at the kitchen socket, and I can't see any possibility of Jeremy simply dialling his own house number using that phone, either with his phone and answer machine disconnected, or not because with the round finger dial phone having no last number dialled facility it would have been of no use to him! And, besides Jeremy would then need to get back to his cottage, get cleaned up and make his unanswered call back to the farmhouse, but in order for him to do this he would have needed to tap the cradle and get a dialing tone on the kitchen phone at the scene, so that by the time he returned to his cottage, he could try to ring whf back only to get a constant engaged tone!
But, surely that would have been pushing his luck too far, don't you think?
Yes, Jeremy could then go through his script and try to contact the police at Witham and if there had been someone there, he could have told them his prepared script and sent them scurrying to white house farm, but as luck would have it Witham police station was unmanned when he tried to contact them because PS Bews, PS Saxby and PC Myalls we're currently engaged in other duties away from the police station at that time, so Jeremy phoned Julie and she told him to go back to bed, and after which Jeremy spent five minutes or so, looking up the telephone number to Chelmsford police station, and he spoke to PC West at 3.36am...
But...
Remember, there was Neville Bambers call to the police at 3.26am...