The DEA focused on at least five doctors who prescribed drugs to Jackson, trying to determine whether they had had a "face to face" relationship with him and whether they had made legally required diagnoses.[1] At least nine doctors were under investigation.[52] The police wanted to question 30 doctors, nurses, and pharmacists, including Arnold Klein.[3] Klein said that he occasionally had given Jackson pethidine to sedate him, but had administered nothing stronger and that he had turned his records over to the medical examiner.[54]