Depends on the evidence available to the prosecution. In some cases there is evidence that the person is lying, it should be admissible (should be admissible as a defense to a rape charge as well). The standard of proof should be the same as any other crime, proof beyond a reasonable doubt in a court of law. Courts will not catch every guilty party on any crime, so I don't expect it here. Even in this case some will get away with it, like any other crime, but at least some will be caught. Also if jurors know that there is really no substantial punishment for those caught lying, it gives them less reason to believe that they're telling the truth. (No real penalty not to, and no real deterrent to false allegations, if it routinely goes unprosecuted)
What I do expect is that known deliberate false allegations be prosecuted, and they carry penalties, upon conviction, equal to the penalty the falsely accused would have received had they been falsely convicted.
Considering mandatory sentencing in some States like in Florida, a judiciary process which is highly contested, I am not sure anyone would want the party proven to have made a false accusation to "receive" a sentence equal to what the falsely accused party would have received if convicted. In such cases (which as a reminder are isolated incidences of demonstrated false accusations), that is when rehabilitative justice should be implemented. Such as mandated community services time. Preferably community services time scheduled in environments where the party charged and found guilty of falsely accusing will be in contact with detainees and in contact with rape victims. Because the damage such party does is harmful not just and only to an innocent man but also to all rape victims.
Those false accusers do fuel a mentality who considers that a non guilty verdict means that the plaintiff was lying. Or that if the victim does not come forward it is because there is something suspicious going on. I recall on FRDB, several years ago, the first time I shared my own experience (as a recovered rape victim under the specific circumstance of a drug facilitated date rape) that I was "greeted" by a reply containing the remark "your alleged rape". Fortunately, I have the fortitude to take such comments with a grain of salt. But not all rape victims have such fortitude. And for them, such dismissal of their experience can reopen wounds still in the healing process.
Why shouldn't a person who makes a criminal claim, when they know it to be false not be subject to prosecution? Do people not know right from wrong?
I have no issue with charges being filed against such individual. It is how the judiciary system is to handle it where I disagree with you. Ideally, such person is to become a poster-person advocate against false accusations. It will be far more productive if they can get motivated to undertake such task rather than rotting for X number of years in detention.
By receive a penalty, I mean face the exact same consequences as the person who they falsely accuse would get. I see no problem with that, as it is justice for the wrongfully accused, and deterrent to false allegations. I said your alleged rape, as I have no way of knowing what the truth is in that situation, I wasn't there. From my point of view you're an accuser, given that I don't have any evidence beyond what you say. That's not intended to be insensitive, but I have to go on the information I actually have.
I think that penalty should be just as harsh, because I think that having to do community service for a false allegation of any crime, unless the crime itself was punished by community service, is much more lenient than what the falsely accused would get if they were wrongfully convicted.
If a person is falsely accused of rape it's reasonably foreseeable that he can face the following consequences:
Loss of good name that he can never get back.
Risk of physical assault by those who think he's guilty, even if it's not. Injury or death is a reasonably predictable outcome.
If he's (wrongfully) convicted, being imprisoned it's reasonable to believe he will face..
Violence against his person in prison, which can include beating, rape, or murder. Rape can also mean HIV infection. Rapists would rank just above child molesters in any prison hierarchy.
If he survives that, permanent damage to his ability to earn a living, within the law.
If he can gather the resources to do so, where he can legally reside is limited.
Permanent listing on the sex offender registry, and having to always report his whereabouts to the local police.
Given these potential, and reasonably foreseeable, consequences to the accused, I'd say that community service for the false accuser is far too mild a penalty. They just don't match up to what the other person is being put through. I don't think that a false accuser's freedom should be in any way more valuable than the freedom of an innocent person accused.
For the purpose of this post, and any future post, by false accuser, I mean someone who makes an accusation, knowing that it's false. The standard of proof should be the same as any other crime. Proof beyond a reasonable doubt in a court of law.