There’s potentially something strange about the period of time RH describes, definitely. It was suggested at the time that the killer could’ve been lying in wait inside the front garden - perhaps, after witnessing the postman leave, in a time before a succession of Amazon/DPD/Evri/Yodel/Deliveroo/Just Eat delivery guys could be up and down her front path, the killer assumes that no one but JD will come to the door now, so decides its relatively safe to seclude themselves and await her return.
When she does so, she catches sight of a man approaching her from within the confines and safety of her property, is manhandled and the gun is placed to her head - this would give her enough time to scream, but IMO still not much more. When she’s found,
her keys are still in her hand and her handbag is over her arm. JMO, but this suggests to me the assumption made that the killing was swift was correct. HD deduced it wasn’t a robbery gone wrong because JD’s valuables were still present but I’d be interested to know if HD saw any signs of a struggle.
The problem with the concealment theory is the killer would’ve surely needed to know JD was returning home that day. The article
@dotr helpfully linked to earlier provides another nugget of information that weakens the notion she ‘usually’ returned to GA on Mondays:
I’ve posted evidence before that suggests her visits to GA weren’t as routine as has often been assumed. As I and I think
@Hexe have said before, it’s incredibly difficult to stalk someone you rarely, if ever, see. At least with the ‘returns to the house usually on a Monday’ theory we can imagine a situation where even a simple man like BG can deduce a pattern to her movements.
But if the pattern is infrequent and irregular, you’d either have to be incredibly committed to watching her house, hoping for a chance encounter, or incredibly lucky she just happens to walk across your path close to the time you’ve chosen to kill her. Neither are impossible, but - JMO - BG was a ‘busy’ man, he stalked prolifically but apparently randomly; repeatedly, patiently staking out a mostly empty property that offers close to zero returns doesn’t strike me as his idea of a good time. And, if he/the killer had been concealing themselves in that spot before, the chances become much higher that someone would’ve spotted them long before the day of the murder. The risk-reward ratio seems way off, to me.