ST. TAMMANY PARISH, La. — One of the key witnesses in the sex abuse investigation into former St. Tammany Parish Sheriff Jack Strain was arrested Tuesday by Slidell Police on a drug distribution charge.

A Slidell Police spokesman said Mark Finn was found with multiple baggies of methamphetamine during a routine traffic stop on Old Spanish Trail at 6:50 p.m.

Finn was the passenger in the car. Joseph Blackledge, 54, of Pearl River was also arrested for improper lane usage, no seatbelt and on a warrant for failure to appear, according to Slidell Police.

Finn is currently being held at the St Tammany Parish Jail, awaiting bond. The St Tammany DA’s office said they could not comment on Finn’s latest arrest.

A self-admitted career criminal, Finn, now age 49, broke his silence about the alleged abuse by Strain just four days out of his last stint in prison in February. He sat down for an exclusive interview with WWL-TV and partner newspaper The New Orleans Advocate.

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Strain is seven years older than Finn, and Finn alleges the sexual abuse began when Finn was 6-years-old and Strain a teenager.

Finn choked up with tears clouding his eyes when describing what he says happened, but the details he provided were far from fuzzy.

“Sick stuff and I remember this stuff. I remember everything,” Finn said.

But according to Finn, the abuse wasn’t confined to the bedroom. He said it happened in the barn, in the pond, in vehicles and other places around the Strain family property.

Sources close to the investigation have said Finn is one of at least four alleged sex abuse victims cooperating with St Tammany Parish prosecutors in the case against Strain.

RELATED: Sex abuse investigation into former St. Tammany Sheriff Jack Strain sent to St Tammany Parish DA for review

Strain’s attorney has strongly denied the allegations.

But state prosecutors aren’t the only law enforcement with Strain in their sights. Strain has not been charged with any crime but charging documents in a related public corruption probe do name the former St Tammany Parish Sheriff as the target of that investigation.