A convicted rapist will be sentenced on Friday for spying on a teenage girl in a cinema toilet while on an escorted trip from a secure unit to watch a Harry Potter film.
Steveland Robinson, 25, admitted a charge of voyeurism at Hull Crown Court earlier this year.
Robinson was a convicted rapist being held under an indefinite hospital order.
When he appeared in court in January a judge demanded those responsible for the patient to explain to him how the incident could have been allowed to happen.
The court heard how Robinson was escorted to Cineworld in Hull in July last year to watch Harry Potter And The Deathly Hallows: Part Two.
But he was allowed to go to the toilet by himself and went into the ladies where he came across the girl, who complained.
At the time of the incident, Robinson was being held at the Humber Centre in Hull, but has since been moved.
Humber NHS Foundation Trust said last month the management "would like to express their apologies to the victim of this distressing incident".
The trust said an internal investigation had taken place and all actions that arose from this had been implemented.
It also stressed that "leave is an important part of a patient's treatment and rehabilitation".