You could say the Gambino crime family has the luck of the Irish. Trouble is, that luck is all bad. Last June, reputed Brooklyn Irish underling Edmund (Eddie) Boyle - who has long been linked with John Gotti's Gambino crime family - was hit with charges related to a 1998 killing outside a Staten Island strip club. Now, an alleged Irish gangster once referred to as a good luck charm by John Gotti himself, has taken the witness stand as a "rat." While on the witness stand this week, 42 year-old Brooklyn native Kevin McMahon - already convicted of racketeering in Florida - was asked about the code he followed while working for mobsters. "Don't rat," said McMahon, "that's ... what I'm doing today." For what it's worth, McMahon never seems to have had it easy. First of all, he stands just 5'2". The New York Post referred to McMahon as "a pint-sized Irish mob underling (who) became John Gotti's lucky charm," thus managing to mock not only McMahon's diminutive stature, but also linking him to the annoying leprechaun who adorns breakfast cereal boxes. But worse than his size, McMahon had a nightmarish youth. Both of his parents were reportedly heroine addicts. He himself was born addicted to the lethal drug, he said in court last week. Things only got worse from there. McMahon's mother ended up killing his dad, with the help of a boyfriend. The mother was tried and convicted, leaving Kevin, at the age of 12, homeless. McMahon wandered the streets of his native East New York, and other rough and tumble Brooklyn streets before - and, really, you could not make this stuff up - finding a cozy spot to settle on property owned by one of John Gotti's top soldiers, Charles Carneglia. It is Carneglia's brother, John, who is on trial now. Back in the eighties, McMahon was so desperate for a helping hand that he took the blood-stained one extended by the Carneglia - and Gambino - families. As if he had not had enough bad luck, McMahon dodged another bullet when John Gotti's son, Frankie, borrowed a bike often used by McMahon. Young Frankie Gotti was struck and killed while riding the bike. This was an accident. Not that that mattered to John Gotti. The driver of the car which struck Gotti's son later vanished. McMahon believed he was on the Teflon Don's bad side. That is, until McMahon apparently played an important role in the infamous 1986 acquittal of Gotti, by a jury many believe was tampered with. This became McMahon's specialty. He later admitted to tampering with numerous other juries aiming to convict Gambino members. When he wasn't rigging juries, McMahon said he was participating in murders, either committing them or covering them up. McMahon testified that Charles Carneglia - a man he considers his "uncle" - committed at least five murders. Among them, the killings of a fellow Gambino mobster at the World Trade Center in 1990, and an armored car driver at JFK Airport. In a sick twist of fate, McMahon is also believed to have made the body of the man who accidentally killed John Gotti's son disappear. McMahon's testimony is the second bit of Irish bad news for the Gambino family in recent months. In mid-2008, Eddie Boyle - who is already serving time in Federal prison - and two other alleged Gambino members were hit with charges related to a 1998 killing outside a Staten Island strip club. Boyle, regularly compared to Jimmy "the Gent" Burke, the Irish gangster who served as the basis for Robert DeNiro's character in Goodfellas, had also been a rising star under Gotti. But he could only go so far. "Given his Irish heritage, Gambino associate Edmund (Eddie) Boyle always knew he could never become a powerful made guy," mob-chronicler Jerry Capeci has written on his authoritative website gangland-news.com. "But that hasn't stopped him from earning a reputation in mob circles as a clever, resourceful money maker who won't buckle under pressure." When it comes to the Irish, if the Gambinos didn't have bad luck, it seems they'd have no luck at all. Contact Sidewalks at tomdeignan@verizon.net