A Co. Tyrone man living in Philadelphia who was once involved in a radical young group with IRA ties in Northern Ireland pleaded guilty to a rake of charges on Thursday, April 16 in a Pennsylvania court, including weapons possession, immigration and tax fraud.

Sean O’Neill, 49, from Coalisland, Co. Tyrone, had been living a quiet life as a builder and bar owner in Philadelphia for the past 25 years but is now facing jail time and deportation back to Ireland.

It wasn’t until O’Neill’s son, Sean Junior, shot a close friend during a drunken underage gun game that O’Neill’s involvement with Fianna Na h'Eireann, a now-defunct extreme youth group associated with the IRA, came out in the open. According to court papers, O’Neill pleaded guilty in Northern Ireland to being a Fianna Na h'Eireann member in 1977.

Sean Junior, now 19, shot his school friend, Scott Sheridan, during Labor Day weekend 2006 while playing with his father’s gun. Police said Sean’s blood-alcohol level was 0.175 at the time, more than twice the adult legal limit.

Sean was found guilty of juvenile manslaughter. He is due to be released this month from his second stint in a juvenile facility.

It was a silencer that police found at the O’Neill’s home after the shooting that provoked an investigation into Sean Senior.

O’Neill, who is free on $1.2 million bail secured by real estate, faces a maximum penalty of 38 years in prison and immediate deportation after his sentence is completed.

O'Neill came to the U.S. in January 1983 on a six-month visa. In April that year, he bought a .38-caliber Colt revolver. O'Neill told the gun dealer that he was born in Irving, Texas, and gave a false date of birth, a story he used to purchase at least three more guns in subsequent years, according to the federal affidavit.

Prosecutors say O'Neill lied about his involvement with the IRA-linked youth group when he came to the U.S. in 1983. They say he married under false pretences just so he could stay here, and then married his current wife Eileen without ever getting a divorce from his first wife.

Prosecutors are also charging O’Neill with lying on several gun-purchase applications, paying some employees off the books at Maggie O'Neill's Irish Pub in Drexel Hill from 1997 to 2006, and failing to file personal tax returns from 2005 through 2007.

O’Neill’s daughter, Roisin, 22, is also due to stand trial this week for a homicide that took place last September.

Roisin, the eldest of O’Neill’s children, is charged with killing a Massachusetts grandmother after she drove up the wrong way on a highway while intoxicated.

Police say that Roisin had a 0.197 blood-alcohol level when she left a bar and drove the wrong way on Interstate 476 early last September.

She apparently traveled three miles before striking the car driven by Patricia Waggoner, 63, of Brimfield, Massachusetts. Waggoner was in the area to visit her grandchildren.

O'Neill Senior told reporters after the crash that his own legal troubles and potential deportation after a quarter century in the U.S. were "the least of my worries."

"To face every day is just too hard right now," he said as his daughter arrived for an October court hearing in a wheelchair.