Fingerprint analysis
This guy’s wife said she needed a new iPad to help her while working from home, but he knew better than she did that it wasn’t the actual reason she was spending hours on her new device. So he decided to make a forensic inquiry.
He noticed that the fingerprints on the iPad’s screen were scattered all over the screen, so he figured out his wife was spending all of her time playing Candy Crush rather than working because of this. Even if you tried, you couldn’t deny that evidence. Case closed!