Hanging doesn't work as a deterrent ?

How do you calculate the numbers for people deciding NOT to kill someone (pre-meditated), because of the possibility of being hanged ?

I suppose being fined for speeding also doesn't act as a deterrent ?

I would suggest it does for most of us....thereby reducing the overall numbers of offenders.

After all, surely it is the reduction of crime and loss of life that is the important thing, not the financial aspect.