At about 5pm on Friday Gardaí were called to the scene on Henry Street where security personnel had detained a suspect for attempting to steal.
The suspect attempted to flee the scene injuring a man in his 80s who was subsequently brought to the matter hospital for treatment of non-life-threatening injuries. The detainee then became unresponsive at the scene, and was later pronounced dead in the matter hospital.
The area of the crime has been forensically examined and a postmortem is being conducted on the deceased.
Gardaí are appealing for witnesses and anyone with video footage of the area from 5pm and 5:30pm to contact them at 01 6668000 or the Garda Confidential line at 1800666111 or any Garda Station.
Gardaí said the incident has been reported to Fiosrú, the Office of the Police Ombudsman.
