Two Kensington men were sentenced to long prison terms Friday by a Philadelphia judge after being found guilty of witness intimidation done at the request of a neighborhood drug dealer.

Leomar Arce, 28, was sentenced to six to 20 years in prison, and Nathaniel McGrath, 20, to a four- to 12-year-term by Common Pleas Court Judge Susan I. Schulman, according to Assistant District Attorney Andrew Notaristefano.

Both were convicted by a jury on Oct. 6 involving a scheme by Kensington drug dealer Joseph McGrath - Nathaniel McGrath's uncle - to persuade a man he stomped and seriously injured over a $50 drug debt not to testify.

McGrath, 27, pleaded guilty to aggravated assault in the March 9, 2010, incident in which he stomped Neil Laun, 30, over a four-year-old, $50 drug debt of Laun's girlfriend.

In August, McGrath was sentenced to 20 to 40 years in prison for the attack, which left Laun hospitalized for more than a week with multiple facial and rib fractures and heavy blood loss.

McGrath made his situation worse when, in prison awaiting trial in May 2010, he called a friend and ordered the death of a regular heroin customer he believed led police to his hideout after the Laun beating.

The contract killing never happened, but McGrath again compounded his problems when, realizing inmate calls are recorded, he went to a prison lieutenant and said, "I told somebody I wanted to have somebody killed. I have to find a way to get out of it."

McGrath's nephew and Arce were found guilty of being involved in a second scheme: offering Laun three payments of $500 if he skipped court appearances and forced the judge to dismiss the aggravated assault charges.

"Witness intimidation is something we take very seriously," Notaristefano said.

Contact staff writer Joseph A. Slobodzian at 215-854-2985, jslobodzian@phillynews.com, or @joeslobo on Twitter.