A major mail theft and check fraud operation across several Central Florida counties was busted this week, resulting in the arrest of 20 people who are accused of running the expansive ring and stealing more than $35,000.

The ring had operational techniques, an organizational structure complete with a boss and upper-level organizers, a detailed bookkeeping ledger and a simple business plan: "If the red flag is up, game on."

They were in the business of mail theft and check fraud, authorities said.

Several of the people arrested are facing federal charges for their part in an organized criminal enterprise responsible for more than $30,000 in losses from fraudulent bank transactions.

The Volusia County Sheriff's Office, along with U.S. Postal Inspector's Service, coordinated the investigation, which spread out to law enforcement agencies in several Central Florida counties.

The investigation, dubbed "Operation Red Flag," was launched in August. The name of the undercover investigation stemmed from how the group would drive through neighborhoods looking for residential mailboxes with their flags up to indicate they contained outgoing mail.

The group would then go through the mail, steal outgoing checks and alter and cash them. It was a fairly structured operation, according to investigators who spent months toppling the group.

"The organization developed a refined method of operation, from the selective targeting of certain neighborhoods or areas, to the method of forgery and culminating in the techniques used to utter the forged checks," investigators wrote in a nearly 100-oage affidavit outlining the group's crimes.

The investigation began after a $250 check was stolen from a residential mailbox in Wilber-by-the-Sea, altered and then cashed for $450. As similar cases started popping up throughout the area, investigators realized they weren’t random, isolated crimes.

As the investigation progressed, three names continued to come up: Sean Drawdy, Lonnie Creech and Bruce Robb.

Identified as the top rung of the criminal organization, the trio is facing federal charges of conspiracy to commit mail theft. So far, criminal charges have been filed against 20 defendants linked to the organization. All 20 have been arrested, with the last defendant being taken into custody earlier this week. Additional charges are expected to be filed as the investigation continues.

According to investigators, the group usually would split up into three-person crews with a rotating cast of participants. Several of the defendants fingered Drawdy as their leader, saying nothing was done without his authorization. He would personally select the targeted neighborhoods and steal the mail and was the one responsible for altering the stolen checks.

Meanwhile, one person in the crew would drive and the third person would cash the forged checks, with the money split three ways, investigators said. Using a mechanical pencil with a fine tip, the checks were altered to change the payee's name. Usually the dollar amount was altered, as well. Often times, only one number would be changed. For instance, one check was changed from $124.27 to $724.47. Another was changed from $100 to $500. On several occasions, banks recognized the checks as frauds and refused to cash them.

Because of his prior criminal record, Drawdy didn't cash the altered checks. However, until his arrest in December, evidence in the investigation shows Drawdy clearly was the organization's leader, investigators said. He even confessed to being the "boss." After his arrest, though, Creech assumed the role of the organization's head. And it was Creech himself who told investigators: "If the red flag is up, game on."

The organization has been linked to more than 70 cases in Central Florida. The Volusia County Sheriff's Office has investigated about 30 of the cases.

In Volusia County, frauds also were committed in DeLand, Orange City, Daytona Beach, Edgewater, Holly Hill, Ormond Beach, Port Orange and South Daytona. The stolen checks were intended for a wide range of recipients: everything from banks, department stores, credit card, insurance and vehicle finance companies to utility firms and cable providers. One of the stolen checks was written by a 78-year-old man to AARP in the amount of $15. The check was altered to read $500. An alert bank teller, however, recognized it as a fraud and didn't cash it. When police caught up to the man who was trying to cash it, he said Drawdy had given him the doctored check to cash. Some of the checks intended to be donations to various organizations.

At least one of the defendants was arrested at a bank while in the middle of a fraudulent transaction. She told detectives Drawdy had altered the check and was waiting for her outside of the bank. Investigators also seized three vehicles and about 100 stolen checks. Some of the stolen checks were found on Creech, while others were recovered during a search of a motel room in Daytona Beach. Also recovered was a ledger that contained the names and Social Security numbers of various victims, as well as biographical information on each one of them. The ledger also contained practice signatures that appeared to have been written with the same style pencil as the one used to alter the fraudulent checks recovered in the investigation. Newspaper articles chronicling various fraud crimes also were found in the motel room.

The 20 defendants linked to the criminal organization include 15 men and five women. Their ages range from 27-47. In addition to confessions from several defendants, investigators have physical evidence linking the organization to a trail of crimes, including personal identification, thumbprints, recovered checks and surveillance video from many of the bank transactions.