When watching "Immortality" a few weeks ago, I was struck by the
fact that Walternate and Alt-Brandon were testing the Cortexiphan on
people, and Walternate commentated that nine of the test subjects "die
in thirty minutes". Also, Alt-Brandon noted they were going to dissect
the brain of the "successful" test subject.

So, this raises some issues:

1) In the real world, such experimentation on humans would cause
outrage if it became public. And it probably land the scientists doing such activites behind bars
(look at what Dr. Mengele and other Nazi doctors did, or the infamous " Tuskegee
syphilis experiment" in the US ).
http://www.cdc.gov/tuskegee/timeline.htm

So, have things in the alt-World got so bad that the government
allows Walternate & co. to perform such unethical acts, or is he doing
it in secret?

2) Who were the unfortunate prisoners being used? Were they criminals (perhaps facing execution or life without parole, and hence deemed "expendable"?). Mental patients? Political prisoners (that prison complex poor
Olivia was locked up in looked pretty big-does Walternate have a "secret police" that arrests his political opponents) ? Homeless people, or other people Walternate knows don't have anyone who'll go to the authorities if
they disappear?