The man handed in a document to Finglas Garda Station last week.
Gardaí investigating the murder of Lisa Thompson in Dublin, are appealing to a man who made contact with officers to come forward.
The mother of two was found dead at her home in Ballymun last week.
Gardaí are continuing to investigate the events that led to the murder of 52 year-old Lisa Thompson. Her body was discovered last Tuesday afternoon at her home in Sandyhill Gardens in Ballymun.
She was stabbed a number of times and her remains may have lain undiscovered for a number of days.
Gardaí say shortly after 7am on Thursday last week, a man handed a document in the name of Lisa Thompson to a Garda staff member at the front door of Finglas Garda Station and left on foot.
Officers are appealing to this man to make urgent contact with the investigation team at Ballymun Garda station.
Gardaí have yet to make any arrests in the case.

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