CENTRAL ISLIP - Police say a Baldwin Harbor doctor is in custody for allegedly selling prescriptions for powerful pain medications.This morning, police arrested Dr. Leonard Stambler, a 60-year-old Baldwin Harbor doctor of internal medicine. DEA agents say Stambler didn't have a medical office, but frequently made house calls.According to court documents, agents observed Stambler selling oxycodone prescriptions from his car, outside his home and on street corners. Stambler didn't enter a plea and his attorney did not comment to reporters. If convicted, he faces 20 years behind bars.A second physician, Dr. Eric Jacobson, has not yet been charged, but has admitted to News 12 Long Island that he supplied prescription pills to David Laffer, the convicted killer behind the Medford pharmacy massacre. DEA agents seized evidence from Jacobson's Great Neck office this afternoon.State records show Jacobson gave Laffer and his wife prescriptions for 3,720 pain pills in less than a year, including some just days before Laffer fatally shot four people on Father's Day.For an extended interview with Dr. Eric Jacobson, go to channel 612 on your iO digital cable box and select the 'iO Extra' tab.Doctor arrested, accused of providing meds to LafferLaffer, wife get max sentences for roles in Medford massacre