It’s based on body language and tears. Criminals can indeed feel remorse but still prioritize getting away with something more. So they continue to keep quiet or deny or pretend.
However, those who feel remorse of some sort are more likely to come clean after a certain point.
In the Chris Watts early porch interviews his behavior was very off. He seemed much too casual about the disappearance of his wife and two small kids. It made most people immediately realize something terrible had happened.
But I noticed he swallowed hard a couple times when mentioning his daughters. The man is super disturbed and morally bereft as we’ve now seen but early on something about that made me believe he’s not a stone cold psychopath (like Patrick Frazee or Scott Peterson, for example), and I predicted early on (on the threads) that he would quickly confess.
He did quickly confess (partially) but he also implicated his poor, murdered wife and blamed her for the murder of his kids. That was horrible. And not at all what I expected.
However, he ultimately did plead guilty and did confess to all the murders.
Just those small throat swallows predicted that for me.