before the transition* or before they transitioned* (not sure which one you meant to write)

And before SHE went to prison, I see no reason to say he other than being a anti-trans shit stain. The timing of the transition doesn’t matter at all, a person who is transsexual should be called the gender they know they are independent on if someone is talking about before their public transition. A person is their gender and should be called so for any time in their life unless they have specifically said that they want to be called their biological/sexual gender when others talk about them before their transition.