I could have shot of explaining it, though of course this is pure speculation.
Guede breaks the window and climbs up to enter the cottage about 8:50pm. He starts to have a look about Filomena's room, note that this room isn't actually ransacked, but gets the urge to go and so heads to the far bathroom to relieve himself.
While on the head he hears the front door open and realises that someone has come home, so after finishing up, he tries to sneak out the front door, meaning he doesn't flush, but finds that it is locked due to the latch being broken. He's now locked in.
He decides to confront the occupant and get the keys, so heads down to Meredith's room, they fight and he stabs her three times. At some point here he pulls up her t-shirt and removes her bra, then sexually attacks her as she bleeds to death.
Suddenly realising what he has done, he runs to the bathroom, get the towels and comes back to try and stop the bleeding, but realising it is too late he goes back to the bathroom, cleans off the blood on his hands and tries to wash the leg of his pants.
He then heads back to the bedroom, sees that Meredith is indeed dead, and covers her, perhaps as a mark of respect for the dead, perhaps to hide what he did from himself, or others, perhaps all of the above. He grabs the money, keys, and phones, locks the door to prevent discovery of the crime till at least the next morning, and heads out and down into the park where he would either accidently or deliberately use the phones just after 10pm.
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