Final plea entered in Columbia drug ring case Ariana Costakes January 17, 2012 The News NEW YORK — The last of five students implicated in a Columbia University drug ring pleaded guilty Tuesday to attempted possession charges, according to the AP. Adam Klein, 21, of New Jersey admitted he sold LSD to undercover officers in one of the biggest drug busts conducted in a New York college, the paper said. Klein must complete five years of community service along with Michael Wymbs, 23, of New York, and Jose Stephan Perez, 21, of Atlanta, who took similar pleas. Harrison David, 21, of Massachusetts pleaded guilty in July to selling cocaine to an undercover officer in exchange for six months in jail and five years of probation, according to Bloomberg News. The fifth defendant, Christopher Coles, 21, will be cleared upon completion of a rehabilitation program. Manhattan Supreme Court Justice Michael Sonberg previously rejected requests from Klein, Wymbs and Perez that they be entered into similar diversion programs. Promoted Content Logging In... Profile cancel Sign in with Twitter Sign in with Facebook or Name EmailNot published Website Comment Notify me of follow-up comments by email. Notify me of new posts by email.