[DiogenesLamp]

The killers didn't even claim to have witnessed any crime happening in their presence, nor were they aware of any felony having been committed.

"In their presence" is not the only allowable condition. "Immediate knowledge" of a crime is adequate to justify a citizen arrest. They had immediate knowledge of the crime.

You are ignoring the portion of Georgia law that states "immediate knowledge" is an acceptable alterantive.

[AnotherUnixGeek]

"In their presence" is not the only allowable condition. "Immediate knowledge" of a crime is adequate to justify a citizen arrest.

The killers had no immediate knowledge of any criminal activity by the victim, as their own phone recordings make clear. They had their suspicions, which do not amount to "immediate knowledge".