In the black market of Maryland's prisons and jails, where the right price can secure cellphones and drugs, transactions unfold through a complex system of currency. Among the key elements: 14-digit codes, prepaid debit cards and text messages.

One brand of cards -- Green Dot -- is so ubiquitous that it has become part of the lexicon on the inside. The recent federal indictment of two dozen inmates and corrections officers in an alleged Black Guerrilla Family corruption scandal at the Baltimore City Detention Center notes several instances in which suspects refer to "dots" in transactions.

Corrections officials have fought for years against illicit commerce -- cigarettes, cash and even bars of soap have been used in trade among prisoners. But recent allegations suggest that such prepaid cards have emerged in concert with cellphones as an efficient way to move capital around, into and out of corrections facilities.

Though there are other companies that provide similar services, Green Dot pops up repeatedly in the recent BGF indictment, in several other recent Maryland cases and in news reports from around the country. In some instances, the payment system has also been used by inmates demanding money in exchange for protection.

U.S. Attorney Rod Rosenstein said Green Dot cards have become the primary source of payment among gang members and other inmates in the city jail. Using a simple code number to make transactions makes the cards hard for authorities to detect, he said.

"Once a person has a Green Dot account number, people can add money to the account in many ways without anyone being able to trace it" he said.

Green Dot Corp. is just one of many providers of this type of card, and there is no allegation that the company has done anything illegal.

The California-based company declined to comment for this article. It says on its website that it has millions of customers who can use its products to access banking services such as ATMs and online bill payment. The company collects identifying information about account holders, which according to court documents helped the FBI locate a suspect's home in the BGF case.

Such cards, like phones and many other outside conveniences, are banned among inmates. No cash is allowed at the Baltimore jail.

According to court documents from the recent federal indictment, inmates would receive text messages on contraband phones containing 14-digit codes linked to Green Dot "MoneyPak" cards sold in stores.

The codes can be traded within the facility or used to transfer funds to linked Green Dot debit cards held outside jail or prison. Green Dot cards are not backed by a checking account or line of credit.

A recorded conversation detailed in an affidavit from the case illustrates how authorities believe gang members used Green Dot cards.

Inmate Steven Loney allegedly told corrections officer Taryn Kirkland in a Jan. 21 phone conversation that he needed help with some bookkeeping. "Go get your notebook and write some of these dots."

She retrieved a ledger of Loney's drug customers and transactions from under her bed, according to court documents. It included several names and the corresponding MoneyPak code numbers.

The recent indictment included 13 corrections officers along with a dozen alleged gang members. Federal authorities describe a world of corruption including sex and drugs -- facilitated in part by money exchanged through the Green Dot cards.

Tavon White, named in the recent indictment as the BGF leader at the detention center, boasted that he was able to make $16,000 profit in a single month, which prosecutors say was laundered through Green Dot cards and the purchase of vehicles. "That ain't bad for a whole month," he said in a wiretapped phone conversation.

But Green Dot cards have been noted in several Maryland investigations dating back to at least 2008, described as being used for extortion schemes and to sell copies of the Black Guerrilla Family handbook.

A Drug Enforcement Administration agent described such cards in 2010 court documents as "simple and advantageous for incarcerated individuals."

Green Dot cards cannot be used for any legitimate purpose within the corrections system, according to Mark Vernarelli, a spokesman for the Department of Public Safety and Correctional Services.

"The best way to reduce or eliminate Green Dot usage is to combat illegal cellphones, which the department has been aggressively doing for nearly six years," he said. Vernarelli added that investigators pursue cases when Green Dot codes are discovered on contraband cell phones.

At a 7-Eleven on Charles Street in Mount Vernon, a rack of Green Dot cards stands by the door, and manager Hirsh Choksi said they are popular. A MoneyPak card costs $4.95 and can be loaded with an amount ranging from $20 to $500. Choksi said $200 is a typical amount.

"It's easily accessible," he said. "Anybody can walk in, we don't have to check ID or anything."

For years, cigarettes and other goods were used as a basic unit of exchange in prisons and jails, said Stephen E. Lankenau, an associate professor at Drexel University's School of Public Health who in 2001 studied the cigarette black market at 16 detention facilities.

"I saw them using things such as potato chips or bars of soap, things available at the commissary," he said. "Now it sounds like it's moving to more sophisticated alternatives. It doesn't really surprise me. You can come up with some clever ideas when you're sitting inside a prison cell."

Without electronic transfers, moving cash around was a dirty business involving rubber gloves, lubricant and body cavities, according to retired Florida warden Ron McAndrew.

If an inmate wanted to transfer money to the outside, he would have to pass it to a visitor to smuggle out, McAndrew said. Cash was also vulnerable to detection -- McAndrew said he once seized almost $6,000 from an inmate, money that represented the proceeds of almost a decade inside.

Scattered news accounts point to the growing use of such cards -- both as a method of exchange and as a way for criminals to extort money from their fellow inmates' families.

This year, for example, the Atlanta Journal-Constitution reported that a woman was sent text message pictures of her brother, bloody and beaten, followed by a message from someone in a prison in Michigan. The sender said he would kill the woman's brother if she did not send $1,000.

The request: Put the money on Green Dot cards. Authorities there said the problem circles back to contraband cellphones, without which illegal activities would be harder to coordinate.

In a 2008 federal indictment that established the BGF's far-reaching influence over Maryland correctional facilities, federal agents wrote that the gang offered "protection" to newly arrested detainees by requiring them to pay money through prepaid credit cards. Those who did not pay would be targeted for violence.

Such extortion plots already existed, but through more traditional transactions. Maryland prosecutors in 2008 brought charges against a former corrections officer named Fonda Deneen White and her boyfriend, an inmate and high-ranking Black Guerrilla Family member Jeffrey L. Fowlkes.

The two pleaded guilty to depositing 180 checks, money orders, cashier's checks and postal orders into White's personal bank accounts -- all from prisoner bank accounts and family members of prisoners.

The case began when an inmate's mother told the FBI she received threatening phone calls from inside the prison in 2007, demanding money in exchange for her son's protection.

"You're not gonna turn this into a game, cause it's a game you don't want to play," White said on one call. On another: "We understand violence."

When Drug Enforcement Administration agents in July 2010 raided the home of Alicia Simmons, a corrections officer later convicted of being a contraband smuggler for the BGF, among the items in her home were Green Dot cards in the names of both Fowlkes and White.

One woman who recently contacted The Baltimore Sun described sending money to her son using Green Dot cards while he was in the Baltimore jail facing an assault charge two years ago. The son said he needed the money to buy cigarettes. She said she sent $50 to him three or four times by calling a cellphone number and giving the man who answered the number.

"It was somebody inside that jail," she said.

Eventually, the woman, who asked not to be named because she fears retaliation, stopped sending money. "He said, 'Mama I need that money, I have to have that money.'"

One employee who works at the Baltimore Detention Center, who spoke on condition of anonymity for fear of being fired, said such cards are ubiquitous behind bars. They are used for every transaction that occurs, whether between two inmates or between an inmate and a corrections officer, the employee said.

"If they proposition me to bring something in, they'll say, 'I'll give you $150 to bring this cellphone in,'" the employee said.

Wallets are among the few personal items that officers are allowed to bring into the facility, the employee said, convenient for slipping a card into unnoticed. A wad of cash would be more conspicuous.

"That's the currency exchange throughout the jail with inmates," the employee said. "If you want to buy some weed, you get the money through the Green Dot."

Transferring money into jail or prison

A recent federal indictment described how Green Dot cards are used by inmates at the Baltimore City Detention Center.

Step 1: A person outside buys a "MoneyPak" card, sold in denominations between $20 and $500.

Step 2: The card bears a unique 14-digit number, which the buyer sends to an inmate, often via contraband cell phone.

Step 3. The inmate can trade the code as currency within the facility or transfer it to a linked debit card outside the jail or prison.

Sources: U.S. District Court, DEA ___

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