People go to hospitals to get well. We all know that medical care involves risks, but what patients don't expect is that the doctors, nurses and other staff members charged with their care may deliberately cause them harm. As an important recent case demonstrates, that's exactly what can happen without stronger controls. David Kwiatkowski was a medical technician and a prescription-drug addict who worked in more than a dozen hospitals in eight states. He stole the painkiller fentanyl that staff members had prepared for patients awaiting cardiac catheterizations.