In defence of murderers and rapists

I really have to stop agreeing with the Green Party, but I am unconvinced of the merits of a retrospective law change to ban people previously convicted of murder or a serious sexual offence from operating a taxi.

I am 100% in favour of this being a restriction for the future, but if someone has been driving a taxi for 20 years with no complaints, it seems unfair to take away their livilihood because of something they may have done in the 1970s.

The ban should take place for any convictions after the bill is passed, not for historic convictions if there has been no other issues with a driver.