How do you suppose that an ordinary, run-of-the-mill inmate goes about "jamming" an electronically operated cell door so that it can't be opened?
Sounds like part of a well-orchestrated "hit" to me.
Suspects?? More than just a few -- The investigation can begin with the victims, their families, and friends of over 30 years for starters.
And another twist -- With the death of the creepy Geoghan goes decades of secrets, names, and pssible "accomplices" during that time. One more reason for the hit.