As you might be able tell from my sidebar, I've been watching a lot of Law & Order lately (all three series that play regularly), and one thing that I've found myself thinking in a number of episodes is that statute of limitations laws often serve injustice more than justice. A serial rapist will go free if they discover who he is one day beyond the five-year statue of limitations. Some crimes don't have a statute of limitations, but a five-year statute of limitations for rape sounds pretty unjust to me given how serious a crime rape is.
I had similar thoughts when we heard about the string of Obama appointees earlier this year who had committed federal crimes by lying on tax forms, sometimes for serious amounts of money, but it was long enough ago that there were absolutely no legal consequences or even requirements to pay up. It just strikes me as unjust. They're criminals, but it's illegal to prosecute them. They ought to be held accountable. So the law seems unjust.
Without doing any research on the history of statutes of limitations, I'd been having that thought. I never got around to exploring the justifications for such laws, though, but I finally did get an explanation on a Special Victims Unit episode (season 1 episode "Limitations") of why there are statutes of limitations. I'd seen this episode years ago, but I guess I hadn't been paying attention well or maybe wasn't raising the question, because a judge explains the original reasoning for such laws in an explanation for how he decides an issue:
The statute of limitations has a long history in common law. It exists to ensure that the defendant receives a fair trial, to make sure that the recollections of witnesses, if any, are fresh, to pressure the government to file charges in a timely manner, and so that, rightly or wrongly, accused citizens need not live their life in fear of the government pursuing them after a long delay.
There seem to me to be three arguments there.
(1) Fair trials require witnesses to have fresh recollections, and a statute of limitations decreases the chances of too-old memories from being used to convict someone unfairly.
(2) Delay in filing charges is bad, and it's good to motivate the government to do so quickly. Statutes of limitations motivate the government to do so quickly, or they'll lose the chance.
(3) It's bad to let the accused live a life of fear of being pursued for a crime after a long delay, and statutes of limitations prevent that.
I have to say that I find these reasons wholly unconvincing. The first one has some merit. The problem is that we don't apply this consistently. Some crimes have no statute of limitations. Maybe it's supposed to be a balancing act, where crimes that are more severe are important enough to allow delayed prosecution in cases where they discover better evidence much later. But if so, why is rape one of the less severe crimes? It shouldn't be. So if this line of reasoning is going to justify some crimes having statutes of limitations but not others, I think we need serious revision of which crimes have them and which ones have longer or shorter limitations. Five years for rape but none for murder seems grossly unjust.
The only other justification I can think of if that rape somehow by its very nature has more risk of unfair trials if there's a delay. Is that so? It's true that rape more often has "he said/she said" kinds of considerations, but it's not more often dependent on testimony than murder. They like to have testimony in both cases, and "he said/she said" testimony should never be enough to convict someone of any crime without further evidence or further testimony. That goes for murder too. It's more difficult to reconstruct motives later on, and that applies to murder too. So I'm not sure this saves the argument.
The second reason also has something going for it. I can understand incentives to get the government to file charges in a timely manner once they have enough evidence to do so. On the other hand, the U.S. Constitution has a double jeopardy prohibition (which I also think can serve injustice often enough, but I doubt it's going away any time soon). If prosecutors bring charges when they can't win a case, and they could have waited until they had a better case, then they might lose the chance to get a conviction. So there might be legitimate reasons to delay even if the person is guilty. If they're not sure who is guilty, then of course they should delay. But is the statute of limitations of five years for rape going to make much difference here? Presumably if they haven't filed charges in five years it's not because they're dilly-dallying. It's because they don't have the evidence. But then when you get the evidence, shouldn't it be fine to pursue it even if it's six years from the crime? So I don't see how this really discourages incompetent delaying enough, and it does prevent morally legitimate pursuit of prosecution.
I have even less sympathy for the third argument. It's true that I wouldn't want the government potentially after me my entire life to prosecute me for something I didn't do or even something I did do, but why should that affect whether we allow it? No one wants to be prosecuted. If they didn't do it, we can hope the process allows enough reasonable doubt, and that's no different with a trial 20 years later than it is with a trial the same year as the incident. If they did do it, then the fear is about avoiding something the person deserves, so we shouldn't cater to that. I don't see how this is all that good a reason. Maybe there are some negatives, but does it justify not being able to prosecute a rapist for a crime committed six years ago when new evidence identifies the perpetrator when it was unknown previously? I don't think so.