I think we need a three strikes and you're out system for extreme violence and sexual offences...
just like the pedophile who was killed after living in the block of flats this guy had a string of sexual offences... sure someone commits an offence once they go to jail, get let out on probation put on the sex offenders register... then they do it again - tis not like they've stolen something because they're starving and need to eat, they're just unable to control a sexual urge or control their anger... they get a second chance but are told that is it... they then commit a third offence - just lock them up for life, they've demonstrated it can't be controlled, they clearly are just ****ed in the head, get them off the streets and put them away. If there is/was a treatment option then that needs to be tried the first and second times they commit a serious assault or sexual offence.
In fact I'd like to see exponentially increasing sentences for crimes in general too - someone with multiple repeat burglaries, just keep them in for even longer each time they get caught