Biometrics have lots of problems. Even assuming the data is read-only secure (by which I mean someone can't substitute their fingerprints for yours, or yours for some known criminal!) you still have an insurmountable problem.
Using the Jacqui Smith example above, her biometric data (fingerprints) are now out in the wild. Even barring Misson-impossible style physical imposture scenarios, the real problem is remote verification (ie over the internet).
The computer doing the checking is NOT checking your fingerprint(s). It's checking the *digital representation* of your fingerprints, sent from God-knows-where. That means A) you can't verify it and B) once the biometric is compromised, you're screwed. You can't replace your fingerprints or your retinal pattern--that's the whole *point* of biometrics.
So what biometrics gives you is an irreplaceable piece of data that is easily stolen and used to "prove" a criminal is you.
Sound like fun?