The body of Paul Smith, 34, was found in a ditch in Ballough, near Lusk, shortly after noon yesterday.
It is understood the underworld figure, from Finglas may have kept horses in a field near where his body was found.
Smith, who also had an address in Dunleer, Co Louth, had been missing for three days.
Gardaí were investigating his disappearance when they discovered his body in a field at Ballough, just off the M1 motorway.
A postmortem was being conducted last night. He suffered gunshot injuries.
Smith was a well-known criminal in the Finglas area and was a senior lieutenant in a gang run by Paul “Farmer” Martin.
Martin, 39, from Kippure Park, Finglas, was shot dead last August. Gardaí suspect he was killed on the orders of Finglas’s top crime boss.
Smith was a suspect in the shooting dead of Graham McNally in Coldwinters, Finglas, last January. McNally, 34, was a right-hand man of the local crime boss.
Gardaí are investigating if Smith was shot dead in retaliation for that murder.
Smith, who was married into Martin’s family, had a number of men working for him.
Garda search teams combed fields all day yesterday, while colleagues from the Garda Technical Bureau examined the scene where the body was recovered.
The gun attack is not thought to be connected with the discovery of a man’s body at 5.15am on the junction of Cardiffsbridge Road and Tolka Valley Road in Finglas.
The deceased, named locally as Maurice Martin, had suffered several stab wounds. The area was covered in blood and gardaí suspect he may have been trying to flee his attacker.
There were local reports that Martin, 21, had been drinking earlier in a nearby field. He had addresses in O’Devaney Gardens flat complex in the north inner city and Co Meath.
About 12 hours later, another young man was shot by gunmen on a motorbike at Casement Park, Finglas.
He received injuries to his behind and was taken to the Mater Hospital. Gardaí recovered a bloodied tracksuit top at the scene.
Gardaí have no evidence to suggest any of the three incidents are linked.
Meanwhile, in the north inner city, a 34-year-old man is in critical condition after a serious assault in Summerhill Parade on Thursday night.