Of course I support locking people up if they commit crimes, I just don't support the push to make sentences ever longer as it doesn't work.
If 15 years isn't a deterrent for a crime then 30 years won't be either. The whole point of the justice system is lessen crime. The more money you spend on prisons keeping people locked up, the less money you have to spend on police officers to help keep crime down.
Not that I'm a fan of speed cameras... But when you see a speed camera, do you not slow down?
Its because you know you will be caught (the true deterrent). You're probably less likely to slow down if you see "road work, fines doubled" signs.
Human nature, it's not the severity of the punishment that deters us, it's the chance you can get away with the crime or not without being punished.