They only get out on parole if the board (or whatever the UK's equivalent is) believes they have learned a lesson and are safe to reenter society. If not then they stay until the next board meeting. I have a hard time imagining they would get out after 20 years for murder without the board being pretty damn sure they are no longer a danger to society.
As gross and heinous as these crimes are, I will never favor life-without-parole or the death penalty for minors.
I did the same. I talked with my primary care doctor first and was put on a 6 months wait list for the endocrinologist. While waiting, I made an appointment with PP for about 2 months out (ours are booked far in advance unless it's urgent like an abortion or STI testing) but got it within a few days of meeting with the PP doctor. Transferred to my Endo once they were available.