What she did was ****ty, but he's also an ******** if he's been a father to this children and they've grown attached to him and he doesn't want to pay for them now he knows they've not got his DNA.
Family isn't just your 'blood'.
I don't think the system is "supporting women in committing fraud" and that " she is rewarded for it by getting child support" because the focus here is on the needs of the children: they're gonna need money for upkeep and it needs to come from somewhere, and they clearly think the 'best' (or 'easiest' in that they can make someone else pay rather than the government) is for him to pay. Unless she's a crappy mother as well as a crappy girlfriend, the money will be spent on the children.
To be fair, although they may not be related to him, he did act like a father and he thought those were his children. It's not their fault their mother did some terrible ****, they don't deserve to be 'punished' (i.e by him disowning them or whatever he's trying to do). He's a sh*t dad if he doesn't want to help his kids (even if his sperm wasn't involved in making them - how many ****ing years have they looked up to him as a dad and him seen them as his children?).
It would be a waste of time and money to charge her. It seems a bit extreme to charge her simply for not putting the biological father's name on the certificate: perhaps she herself was unsure of who the parent was? What should happen is that the man should be able to opt out of paying child support as he falsely believed they were his children. If he was a decent father, I imagine he'd still want to support them.
Tbh I think it's unfair how men are expected to pay child support for children they don't want (this is a sort of vaguely linked point), I think there should be an opt out system in pregnancy. If the woman wants to keep a baby, but the man doesn't want to be a father (and obviously he can't force her to abort that would be just wrong, just as it would be just wrong to force her to remain pregnant when its her body and health being affected), he should be able to legally give up his rights to the child which would also mean he wouldn't have to pay child support (and the woman should be informed of his decision). This should be done as soon as he finds out she's pregnant.
Probably would cause all sorts of problems but it'd be nice, and a lot fairer. Feel sorry for all the guys who don't want to be a dad but are forced into paying child support because the legal system doesn't allow them to opt out. Personally, I think it's so the government doesn't have to fork out more benefits for children with low-earning mothers - they can get someone else to pay directly instead.