Four New York City residents are charged in Massachusetts in a scheme in which they bought thousands of dollars' worth of electronics with counterfeit $100 bills, then returned the items for cash, police say.

The suspects all pleaded not guilty at their arraignment Thursday in Attleboro District Court a day after their arrests in nearby North Attleborough.

The four were arrested after returning more than $5,000 worth of iPads, digital cameras and other merchandise to a Target store that had allegedly been bought earlier in the day from a Target in Westborough, Detective Michael Elliott said.

The scheme may have cheated Target and other retailers in Massachusetts, Rhode Island, Connecticut, New York, New Jersey and Pennsylvania out of $50,000 in the past two months, he said.

Police were tipped off by suspicious employees at Target, who also alerted the U.S. Secret Service, the agency that investigates counterfeiting. The Secret Service assisted in the arrest, Elliott said, and have been investigating.

"The suspects have been doing this for some time," he said.

A message left at the Secret Service's Boston office was not immediately returned Friday.

The man accused of being the ringleader, Shaun Whitehead, 24, was held without bail at his arraignment on a fugitive from justice charge out of Iowa, Elliott said. He was held on $20,000 bail on the Massachusetts charges, which include larceny, receiving stolen property, conspiracy and possession of counterfeit money.

His alleged co-conspirators, Sharon Holloway, 32; Stephanie Cancel, 19; and Jerel Bryan; 22, face the same charges in Massachusetts.

Holloway was ordered held in jail on $10,000 cash bail and Bryan and Cancel were each ordered held on $5,000 cash bail.

Cancel was in possession of one fake $100 bill, but police recovered thousands of dollars' worth of phony bills in Westborough, Elliott said.

"They were good quality," he said. "If you put them side by side with a real one, you could hardly tell the difference. They just had a little bit of a different feel to them."

Whitehead and Bryan allegedly tried to eat Target sales receipts after their arrest, police said.

Holloway told investigators she knew the money was fake, but was taking part in the scheme for the first time. Her lawyer told The Sun Chronicle of Attleboro that she is from Rhode Island and had accepted a ride from Whitehead to the area to visit family. North Attleborough is on the Rhode Island border.