Well he had something to do with Roy DeMeo. Thats why the Paul Hoffmann murder happened.
Anthony Bruno verifyed it.
As for his association with DeMeo, the late Kenny McCabe of the NYPD confirmed that Kuklinski had been at the Gemini Lounge in Brooklyn (DeMeo's headquarters) on several occasions. DeMeo was under surveillance in the early '80s, and the police routinely took down the plate numbers of the cars parked around the bar. Kuklinski's was one of them.
http://www.amazon.com/Immortal-Monster-Crimescape-Anthony-Bruno-ebook/dp/B005DN1UG2https://groups.yahoo.com/neo/groups/americanmafia/conversations/topics/7489