We are all appalled by such crimes but Human Rights don't really come into this case. This is a definite prison sentence if they are caught at least 5 years and it will be in a closed prison.
Much of the 'holiday camp' idea you talk about is in regard to Open prisons , violent offenders are not sent to them. When someone is sentenced to prison they all at first go to a closed prison for assessment. There are 4 categories A to D, a cat A prisoner is either extremely violent or considered to be a high risk of escape attempt, this is the highest level of security and can only be housed at one of the high security jails. Violent offenders are normally cat B and can get reduced to cat C for good behavior after several years. ' ordinary' prisoners are normally cat C from the start , still a closed prison but with more privileges , however poor behaviour will mean a transfer to a B cat . Open prisons are only for cat D prisoners the lowest security level , many of these are long term prisoners near the end of the sentence , the idea is to give them a more 'normal' life to prepare for release. Some cat D open prisoners are allowed to work outside the prison and earn money that is kept until release. There is still the threat that they can be returned to a closed prison if they do anything wrong.