Trump is not being investigated for murder, so why on earth would that statute of limitation be relevant?
You know, you're right. I'm sure the various prosecutors who have been pursuing Trump for the last five or six years, constantly leaking hints to various MSM outlets that they were "closing in" on Trump, that they were finding all kinds of big problems in the Trump organization... I'm sure they were only interested in crimes other than murder, and even though a (disgruntled and publicity-seeking) member of Trump's own staff had made such an accusation, those prosecutors — who everyone knows were politically motivated — immediately drew a line in the sand.
"Oh, no, mercy me, perish the thought!" said they. "We'll pursue any accusation of any conceivable financial crime against Trump, but we cannot look at any other subject, no sir!"
I see that clearly now that you've pointed it out.