He became eligible for release in 2013 and again saw the Parole Board last month, but at this hearing did not seek parole
Since his previous meeting with the board he had undertaken "extensive one-on-one psychological counselling", in which he was doing well.
"Good progress has been made by Mr Glen, but obviously more is required," says the Parole Board decision, released today.
"At the moment Mr Glen remains an undue risk to the safety of the community and parole must be declined. He should, if at all possible, progress carefully in the reintegration phase of his sentence, which would include considerable work being undertaken in formulating a sound release plan.
"But release is still some way off."
For now, Glen remains in a self-care unit, where prisoners learn to look after themselves in preparation for release.