A woman is in a critical but stable condition in Jersey's hospital after being stabbed multiple times at a Morrisons in St Helier on Saturday 18 November.
The 34-year-old member of staff was treated by paramedics following the incident at Castle Quay at 1:30pm.
A 55-year-old man, who police say is known to the victim, has been arrested on suspicion of attempted murder and remains in custody.
Since the incident, forensic experts have been seen entering the store.
Sandpiper management and staff say they are "shocked and saddened following a devastating incident that caused serious injury to a member of staff.
"Sandpiper management and staff are shocked and saddened following a devastating incident that caused serious injury to a member of staff yesterday (Saturday).
"Our priorities are to ensure everything possible is being done to care for our much-loved colleague and their family who are foremost in our thoughts. We are offering full support to the police and other authorities and also supporting fellow members of staff affected by the incident.
"As this is now an active police investigation, we will not be commenting further."
The Morrisons shop is cordoned off for a second day as investigations continue.
Police are appealing for witnesses with any information to call them on 01534 612 612 or anonymously via Crimestoppers on 0800 555 111.
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