We now have a word for it, and it's even more of a mouthful than "hypergamy":
The official term for lusting after people with a criminal record is known as hybristophilia and has been studied by Dr Philippe Bensimon at the University of Montreal.

The behaviour is best demonstrated in cases of infamous serial killers in the US, such as Charles Manson and Ted Bundy who are widely known to have received fan mail of a sexual nature from women.

For those working in correctional facilities in the US, hybristophilia is said to affect almost 4 per cent of prison workers, which includes not only prison guards, but psychologists, social workers, nurses, teachers, and other professionals.

Those workers who act on their desires can be punished under US law, with the broad description of sexual misconduct incorporating everything from romantic relationships to obscenity directed at an inmate.

'It's taboo. All penal institutions, without exception, are affected by this phenomenon, but prison administrators try to deny its existence: they don't even talk about it in staff training,' explained Dr Bensimon.
She's not psycho, she's just a hybristophiliac. However, it would be useful to know if that 4 percent of prison workers means 4 percent of FEMALE prison workers, or if it means what it says. Because, assuming that 80 percent of prison workers are male, that would mean that around 20 percent of women are hybristophiliacs.

Which actually sounds about right.