Keep the cookies, Pud, I'll take the wine.
Having been a penpal to a couple lifers myself, I confess that there is a certain novelty in communicating with criminals. It's honestly pretty sad to hear from one whose future is gone.
While I appreciate your concern for the victims' families, I sincerely question whether they'd enjoy a penpal relationship based on the wounds from a crime. Besides, we don't know for certain that they don't have penpals.
For some people, writing to inmates is part of their ministry, for others, a sensational exploitation of those who somehow ran afoul.
In my case, it was for art. There are many very talented artists incarcerated in the USA and I admit that I enjoyed the novelty of seeking commissioned pieces. I am also involved in more proactive, community oriented projects, this is just one spoke on my wheel of life.