All sorts of bits and pieces coming out.
Times off work with bouts of an unknown illness in the weeks before.
Reports of erratic behaviour while on duty.
Then the indecent assault allegations caught on camera at a McDonald's.
CCTV footage from a bus serving the route Sarah walked and at about the time.
Dashcam footage of his vehicle and ANPR checks on its route.
Serious head injuries sustained when in custody and apparently self-inflicted.
The last one and the first three point to a very disturbed man on the verge of a breakdown or who might have already had one.
The Met is going to take a right pasting over all of this.