There is no one answer to security. It is always dependent on the threat, location and desire. Biometrics has been seen by some as the answer but as you’ll see in the link below it’s not. It is a part of the answer but only a part. The example below is not just security but a method of accountability.
AFP – Five doctors at a Brazilian hospital have been suspended after they were accused of covering for absentee colleagues by using fake silicone fingers with their prints to fool biometric machines.
Globo television showed footage of a doctor touching her finger to the device, then using two fake digits to do the same for colleagues, and taking delivery of slips of paper indicating they had in fact clocked in to work.