( CNN ) -- An Air Force nurse has been charged with murdering three terminally ill patients by giving them fatal overdoses , the Air Force said Tuesday . Capt . Michael Fontana is continuing to work at Wildford Hall Medical Center . Capt . Michael Fontana , a nurse at Wilford Hall Medical Center at Lackland Air Force Base in San Antonio , Texas , also was charged Monday with conduct unbecoming an officer for changing a medical document . `` The charges are the result of an Air Force investigation that occurred after irregularities were discovered in Capt . Fontana 's administration of medications which may have resulted in the death of an end-of-life patient , '' hospital spokesman David Smith told reporters . The nurse was charged with three counts of violating Article 118 of the Uniform Code of Military Justice . `` It is considered murder , '' Smith said . After an Article 32 hearing , akin to a civilian grand jury proceeding , the commander will decide whether the case goes to court-martial . The three deaths occurred in July , Smith said . He cited the privacy act in refusing to divulge the suspect 's age and hometown . He said he did not know the motive but was confident no other patients were victimized . `` We know that there are no other patients involved in this case , '' he said . Fontana , an intensive-care unit nurse who has been working at the hospital since 2006 , the year he joined the Air Force , has been released on his own recognizance and is continuing to work at the hospital , though he is no longer involved in patient care , Smith said . `` As far as we can tell , he has been an exemplary nurse , '' Smith said . Fontana also served as a nurse at the Air Force Theater Hospital in Balad , Iraq , Smith said . His work there was investigated , `` and there was nothing found , '' he said . A call to a San Antonio phone number listed as belonging to Michael Fontana got a message that said , `` Thank you for calling . Due to the ongoing investigation , I have no comment for you right now , but I do appreciate your call and will talk to you soon . '' Relatives of the dead patients have requested privacy , the Air Force said . Wilford Hall Medical Center is the Air Force 's largest medical facility .
Man is accused of giving terminally ill patients fatal overdoses . The man was arrested in the city of San Francisco on Tuesday and charged with felony drug possession after police found a bag containing more than 100 oxycodone pills at his home. He is also charged with conduct unbecoming an officer .