North Philly, May 4, 2001. Officer Sean Devlin, Narcotics Strike Force, was working the morning shift. Undercover surveillance. The neighborhood? Tough as a threedollar steak. Devlin knew. Five years on the beat, nine months with the Strike Force. He’d made fifteen, twenty drug busts in the neighborhood.
Devlin spotted him: a lone man on the corner. Another approached. Quick exchange of words. Cash handed over; small objects handed back. Each man then quickly on his own way. Devlin knew the guy wasn’t buying bus tokens. He radioed a description and Officer Stein picked up thebuyer. Sure enough: three bags of crack in the guy’s pocket. Head downtown and book him. Just another day at the office.

–PENNSYLVANIA v. NATHAN DUNLAP, 555 U. S. ____ (2008), ROBERTS, C. J., dissenting ON PETITION FOR WRIT OF CERTIORARI TO THE SUPREME COURT OF PENNSYLVANIA, EASTERN DISTRICT,