Seems sort of bizarre that the review hearings are done in front of a jury, rather then some sort of panel of people with relevant expertise. The person has already been found guilty, so there isn't really any judgement call to make as far as the facts are concerned.

The cynic in me thinks this is done just because no-one wants to take the responsibility of releasing these people, since if even one goes on to commit a sensational crime, the person who made the call to release them will get pilloried by the public (and probably, by their own conscience). So the jury provides a way to pass on the responsibility for the call.