The body of Mark Desmond, 41, was found at Griffeen Valley Park in Lucan at about 20:00 local time on Friday.
A burned out car was found close to the scene. A handgun has also been recovered.
RTÃ‰ reports that Desmond, who was originally from Ballyfermot, had previous convictions for violent crime and firearms offences.
Police have started a murder investigation after a man was shot dead in west Dublin.