Trans people have always existed
Yes we know that. Nobody here is denying trans people exist or that they have always existed.
It's a recognised medical condition.
So you think it's a medical condition? In that case, according to trans activists you're a transphobe and a TERF and deserve to die in a fire. Sorry about that 
They're not some weird subsection of criminals
Nobody has said they are.
What people have said however if that if self identification becomes law then men who are criminals will take advantage of it. This has already happened in places like the US and Canada where self identification is already in place.
they're normal people who are unfortunately born feeling like they have been given the wrong body
Exactly. They feel like they were born in the wrong body but that doesn't mean they literally were born in the wrong body or that they really are the opposite sex.
And just like your previous comment, according to current trans ideology, this comment would also have you branded a bigot and a transphobe in their eyes.
They aren't evil they deserve our compassion and understanding.
And they have lots of it from us. Just ask any of the numerous trans posters who are regulars here or the parents of trans children who post here.