Search on for Chesco drunken-driving convict

To Chester County law enforcement officials, Sean Owen O'Neill Jr. is hardly a stranger.

In fact, he's often held up as an example in presentations to high school students, authorities say.

"He's like the worst-case scenario," Chester County District Attorney Thomas P. Hogan said Tuesday. "If you're using drugs and drinking, this is where it can lead you."

In 2006, O'Neill shot and killed his best friend at an underage drinking party. Tried as a juvenile, he was sentenced to a residential-treatment program. He served jail time this year after drunkenly crashing his black Cadillac into a house in November 2011.

Now, authorities say, O'Neill, 23, has become a fugitive. He's been on the run from probation officials since testing positive for drugs and alcohol, thus violating the terms of his parole on the drunken-driving charge, they said.

"Sean O'Neill has been a thorn in the side of law enforcement in Chester County for years now," Hogan said.

"Were we surprised when he tested positive and then became a fugitive? No. Are we happy about it? Absolutely not, and if he's in the United States, we'll find him."

O'Neill's attorney in the DUI case, Vincent DiFabio, said he was surprised by the turn of events. O'Neill had been attempting to turn his life around, enrolling in classes at Temple University, DiFabio said.

"I thought he was on a pretty positive track after the last court proceedings," DiFabio said. He said he hadn't heard from O'Neill's family on the matter.

Hogan says it's possible O'Neill has left the country. His father, Sean Owen O'Neill Sr., was deported to Ireland after police found silencers while searching his Willistown Township home after the 2006 death of 17-year-old Scott Sheridan, his son's friend. Owning silencers without a special license is a federal firearms violation, and the elder O'Neill served 18 months in jail before being deported.

"We are following trails in the United States and internationally," Hogan said. "If I knew where [Sean O'Neill] was, he'd be locked up by now."

O'Neill's sister Roisin also has had an encouter with the law. In 2008, while intoxicated she drove the wrong way on the Blue Route, striking a car head-on and killing Patricia Murphy Waggoner, of Brimfield, Mass., a 63-year-old grandmother.

After his release from a residential treatment program in 2009, Sean O'Neill was arrested again in 2011 when he drove his Cadillac into a home's garage in West Goshen. His blood alcohol content registered at 0.25, Hogan said, triple the legal limit.

"We're like, here we go with Sean O'Neill again," Hogan said.

Following a stern lecture from a judge, O'Neill was sentenced to two to six months in prison. He was out on parole when he tested positive for alcohol and illegal drugs earlier this month. Officials then lost contact with the SCRAM alcohol monitor he was required to wear, Hogan said.

"Then they really started amping up the search for him," he said.

Hogan said he has authorized police jurisdictions within the continental United States to extradite O'Neill if he is caught.

In a typical case, Hogan said, he would only authorize extradition from the eastern United States. He said international fugitive cases are rare in Chester County.

"Usually it's like someone fled from Coatesville and might have gotten as far as Downington," he said.

"Quite frankly, if he's left the country, Chester County law enforcement will not shed any tears if he never returns to the United States."

Contact Aubrey Whelan at 610-313-8112 or at awhelan@philly.com, or follow @aubreyjwhelan on Twitter.