I saw the official caution "Anything you say will be used in evidence against you," actually hovering on Summerhaye's lips. 
Summerhaye wasn't sure that he had enough cause to make the arrest.
mnli hypothesis: Summerhaye wasn't sure that he had enough cause to make the arrest. premise: I saw the official caution "Anything you say will be used in evidence against you," actually hovering on Summerhaye's lips. 