I'm no fan of Chris Grayling, but he pointed out that a) Open Prisons have been around for decades; b) the "failure rate" is something like 5 per 100,000 such day-releases; c) he's planning to tighten the rules for people who've absconded previously.
I'd have thought a sensible policy would be to add 6 months to the sentence for the first time a prisoner absconds, 12 for the second etc, as well as pushing back parole. In the long run day releases, properly managed, are an important part of getting prisoners re-integrated into society. The thing that seems to be missing is that somewhere down the line there's not enough willingness to recognise that some people don't want to be reintegrated. Even for all my liberal principles, there has to be a line drawn somewhere. The Skull-Cracker certainly has crossed that line and should surely never be let out again (each time he's gone on the run he's also re-offended within days). I'd have thought that Pickering has crossed that line too.