Two nurses failed to ensure the required checks were made on a vulnerable patient at the mental health facility the Oberlands Centre in the hours before she died, Guernsey's Royal Court has heard.
Restrictions on reporting the trial were lifted by Judge Russel Finch after 10 days of evidence.
Former mental health nurses Rory McDermott, aged 32, and 31-year-old Naomi Prestidge, were on duty on the 11 and 12 October 2017, the night 22-year-old Lauren Ellis died on the Crevichon Ward.
They are facing charges of manslaughter by gross negligence.
Giving evidence, Lauren's psychiatrist Dr Bhintade said he assessed Lauren and advised she be checked every 15 minutes.
But CCTV shown to the court shows Lauren was last checked at 1am on 12 October. No further observation checks were made on Lauren or other patients in this part of the ward until Naomi Prestidge found Lauren on the floor of her room at 2:42am.
The court heard Rory McDermott recorded observation checks had taken place when they had not, and the prosecution argue that minutes after finding Lauren, Naomi Prestidge can be seen on CCTV footage recording observation checks which never took place.
Lauren had a long history of mental health problems and self harm. The night before her admission to the Crevichon Ward, the court heard Lauren had attended the Emergency Department at the Princess Elizabeth Hospital three times.
She had self harmed twice and agreed to stay at the Oberlands Centre on a voluntary crisis admission. She arrived at 10am on the October 11.
At around 11pm the court heard Lauren phoned her mother Dawn Ellis.
In a statement read out in court, Ms Ellis said she later phoned the ward and spoke to Rory McDermott, telling him she was concerned for Lauren's welfare.
The court heard pathologists have determined Lauren's cause of death but they cannot give a definitive time of death.
The legal teams representing the defendants are expected to open their case tomorrow.
Naomi Prestidge and Rory McDermott deny the charges.
The trial continues.