“He just made himself the prime suspect if something “unfortunate” happens to the perp.”
I’ve reminded several people over the years that Perry Mason is dead. People make stupid statements like this all the time. Very rarely does anyone act on them, which is why the police don’t proactively arrest people for spouting off stupid things. Then, occasionally, someone says I’m going to kill so and so, and they do it and everyone says, “Why wasn’t he arrested?” Because “justice” is reactive. If it was proactive everyone with an IQ below room temperature, roughly half the population, would be in prison.
But ... if the murderer's slightly decomposed body gets turned up in a shallow grave in the woods by some hiker's dog ...
Who are the PoPo going to come looking for? Prosecutors and juries love stupid statements. That stupid statement establishes intent; it encourages The State to find or fabricate opportunity and means.
Silence is golden. Wait. The right time will come. If your prey knows it is being stalked you are doing it wrong. When two people know something it is no longer a secret.
The father should have said nothing and waited for 5 years or more to strike.