These two at first glance are POLAR OPPOSITES. In Trial One, Beau doesn't even like Suki (he even goes as far as to call her a "slut") because of how she dresses and flirts with the other prisoners. Suki, meanwhile, takes no acknowledgement of Beau. The only similarity they have is their mutual dislike of Cosmos, but even that doesn't last long.
THEIR OPINIONS ON THEIR CRIMES, HOWEVER? Both of them believed they were in the right, and they basically gave the same answer to the same question.
So then, what changed between trials? They were both "FORGIVEN", and so that affirms that they shouldn't regret what they did, right? Well, it's a bit more complicated than that. (Beau uses strictly they/them in T2... it's not a good thing.)
Beau doesn't regret killing the person they did, but they reveal that they regret what happened to their sister Belle. Since Beau killed their father AFTER their mother's disappearance from the family, of course it would have an impact on their only remaining family member.
Suki is starting to have conflicting thoughts on what she did, as well as her job as a prostitute. She only starts having these feelings after Prisoner No.001; Autumn Yagi is separated from her due to being "too dangerous". Autumn was the only person that Suki felt she was able to have a serious conversation with, but now she doesn't even have that.
"Please don't forgive me."
A "GUILTY" verdict in Trial One could've saved both of them, and I stand by that. Beau would've gotten to explore their gender more freely and come to terms that they are a boy. Suki would've gotten to think for herself if this was the job she wanted or not.
However, because they were both "FORGIVEN", it only led to both of them becoming suicidal. Beau hides in their cell, doesn't talk to anyone, and relies on Cosmos to bring them food. When Suki tries to talk to them, she gets upset that she can't connect with them, and she goes as far as to call them out on being "the worst parts of herself". Suki even mentions Faith & Ruby, and they are by far the two people who want to live the most out of everyone in the prison. She doesn't understand why those two can have hope for someone who's given up on life.