Mr. Weston says he is always on call; his Bluetooth earpiece comes off in public only when he goes to the barber for his weekly $16 trim. His cellphone, he says, holds the numbers of some 100 potential lineup fillers, mostly friends and acquaintances from the Mill Brook Houses, the public housing project in the South Bronx where he has lived most of his life.

He often complains about how people hound him for the chance to make a few dollars through lineup work.

“I can’t even play basketball on the courts or sit here and drink a beer,” Mr. Weston said on a recent afternoon. “People are always asking me if there is a lineup.”

Fillers are paid $10 for a local lineup in the Bronx. For each lineup that Mr. Weston fills in the Bronx, he receives $10; he gets more if he sits in as a filler or if his services are required in another borough.

This is Mr. Weston’s primary source of income. Some days he organizes as many as four lineups; on other days, none at all.

These days, the work has slowed.

“There’s not enough crime now,” Mr. Weston said. “But it comes and goes, and there’ll always going to be knuckleheads stealing phones.”

Mr. Weston said he got his start compiling lineups about 15 years ago, when he was interrupted while eating lunch outside in the Bronx. A police officer asked if he would participate in a lineup and if he could find friends, too.