"Blurring the Statute of Limitations"
No question about it: If you murder someone, you better be prepared to live with it for the rest of your life, maybe even afterwards. As well you should be.
You should likewise be prepared to face criminal prosecution for the murder for the rest of your life -- that is to say, until whenever the authorities catch up with you. This is due to what amounts to a policy decision that Society made long ago, and it is a decision that applies nationwide. Put simply, no one may ever escape prosecution for committing murder merely because too much time has elapsed since the killing. The rationale here is that murder so undermines the "social contract" that it shouldn't be dealt with in any other way.
This "social contract" has in fact been amended in recent years: New statutes now on the books address acts of terrorism that create a foreseeable risk of death or serious physical injury. These statutes of limitations allow prosecutions for acts of terrorism as long as the offenders remain alive, even where no deaths result from the terrorist act. In other words, there is no statutory time bar for prosecuting such offenses in states where such statutes exist. In our age of modern terrorism, it is difficult to quarrel with these laws.
It is for good reason, however, that we do not leave all crimes and offenses interminably open for redress. Lawmakers decided long ago that "the Law" should impose time limits after which neither the government, in the instance of both criminal and civil offenses against it, nor the private citizenry in the instance of civil offenses committed against its members (as victims), can pursue claims against those who have wronged them. Such periods of limitation are intended to benefit both the wrongdoers and the victims (including the government), and do so for a multitude of reasons.