Metropolitan Police Service
The force is believed to be the first in the UK to do so.
In March, police said no charges were likely to be brought for at least the next two years.
Shadow attorney general Shami Chakrabarti said a senior Scotland Yard officer should ‘remember his constitutional role’.
Judge Wendy Joseph QC said it was a “truly terrifying incident”.
In a separate trial he pleaded guilty to possessing indecent images of children and of voyeurism.
"We do not consider that a criminal threshold has been met."
The victim has not yet been identified.
Henriett Szucs was a “very talented” artist.
And Brexit is a "huge driver".
A stop and search order has been authorised for the area.