Stealth’s knowledge / attention to detail

She tugged on the handcuffs again and laced her fingers over Polk’s mouth and nose. “He will asphyxiate in two minutes if you do not place your weapons on the ground and give me the handcuff key.”
“Standard procedure for moving prisoners,” said Harrison. “The key’s never in transit, only at either end of the—”
“The key is in the left front pocket of your pants on a silver ring. Corporal Polk now has one minute forty-six seconds left to live.”

Excerpt From Ex-Patriots, pg 553
Peter Clines
https://books.apple.com/us/book/ex-patriots/id585738393