He's been instrumental in the solving of many Irish crimes, including murders, and now works as a private investigator.
Pat Marry has worked on some of the most high-profile cases in the country - including the killings of Rachel O'Reilly and Gda Adrian Donohoe - and he'll be talking about some of this work at a free event at SETU this Thursday evening (Nov 30).
The public talk has been organised by The Lifesaving Foundation in conjunction with SETU's School of Health Sciences.
It takes place in the Luke Wadding Library at SETU's Main Campus on the Cork Road, kicking off at at 7:30pm.
Ahead of the event, Pat spoke to Damien Tiernan on 'Deise Today' yesterday (Monday).
He gave his view of the riots in Dublin last week but also explained why he became a detective, discussed the importance of a good investigating team, and also spoke about his new book 'Murder at Lordship... The Hunt for a Detective's Killer', being released next year.
You can listen back to Pat Marry on 'Deise Today' by clicking on the image above...