As crime-solving tools go, it may not have the same pedigree as, say, the oversize magnifying glass. But with apologies to Sherlock Holmes, an iPhone — specifically, the iPhone 4 — proved quite useful in helping police officers track down a robber on Thursday in Manhattan.

And at a pace that may shock any reader of a long-winded Victorian detective novel, it was all wrapped up within a half-hour.

The case involved the robbery of a similar iPhone from a handbag store. On Friday, the arresting officer, Robert Garland, shared details about how the low-level crime occurred, and how the high-tech arrest was made.

At about 7 p.m. on Thursday, a cashier at Tuci Italia, at 1393 Avenue of the Americas, near West 57th Street, was taking a break near the entrance of the shop and watching videos on YouTube, Officer Garland said, noting she was wearing headphones.