Nanochange

Someone got killed and you must discover who, out of three suspects, has done it.

Except it's the future. But not that one where crimes are solved before they're even committed. Instead, technological advancement has obsoleted most physical proofs, from photos to fingerprints, leaving little more than testimonials and deductions to solve cases.

In other words, Sherlock is sad, Poirot is happy.

So put on your metaphorical Fedora hat, and go interrogate some poor souls until the truth somehow emerges from a mess of lies.