The financial requirements of this industry resemble in many respects any other economic activity. There is a need shared by all businessmen...for secure transportation and storage of money and monetary instruments. There is an attendant need for ready access to these funds as business exigencies arise...Trafficker funds can be wired by Telex within one day to any bank in the world.

A DEA financial intelligence officer

It used to be that criminals robbed banks. Here they try to buy them. Or at least find a friendly banker inside.

Control of at least two Miami banks had been purchased by large-scale drug importers, sources said, but regulatory officials subsequently obtained changes in ownership. In addition, the sources said, at least three attempts to take over banks have been thwarted by drug investigations.

One investigator says a bank official, acting on his own, traveled to Colombia to solicit traffickers' business.

So the legislature has beefed up the investigative staff of the state comptroller this year and liberalized laws to make it easier to determine the backgrounds of foreigners seeking to purchase state-chartered banks.

In the summer of 1977, when a new cash management specialist arrived at the Royal Trust Bank of Miami, he noted a sharp increase, three to four-fold, in outstanding cashiers checks. Big ones, like $50,000, and perhaps 10 to 15 attributable to one customer.

The bank called the FBI. What followed was an investigation of Juan Evilio Pou, an officer in the bank's international department and a Bay of Pigs veteran. He subsequently left the bank, purchased his own with other associates but eventually left that deal.

Last year Pou was convicted in federal court of a misdemeanor - failing to completely fill out a federal form required when bank transactions exceed $10,000 in cash. Dario Vergara, a supposed businessman from Colombia, had deposited $150,000 in the Royal Trust Bank on Jan. 12, 1977.

The deposit was on behalf of a Cesar Molina, identified by investigators as a narcotics figure.

Then there was Ronald Braswell, who caught in a cigarette smuggling deal and agreed to turn informant. Because of him, authorities eventually busted what they waid was a $500 million-a-year drug ring that was also penetrated by two state attorney's office investigators posing as policemen on the take. One was Martin Dardis, who once tracked Watergate funds.

Dardis recounted in a confidential investigator's memo Braswell's description of the financial operations of a subsequently indicted drug trafficker, Bertie Dias:

"Bertie works through a legitimate bank. The money goes through the Caymans in the form of a cashier's check that is not recorded by the bank...sometimes it's through wire. The money is on deposit here...It goes to the bank in the Bahams to the bank in the Caymans, but eventually it goes to Switzerland and it's transferred by wire.

"The money is in existence, but it's all credit on paper.

"It finally ends up in a numbered account in Panama or stays in a numbered account in Switzerland, and the Colombians get it either through loans or they convert it into one of the numbered accounts in Panama or in Colombia.

"It's a very intricate bookkeeping system."

"In criminal activity," Richard L. Kobakoff of the Drug Enforcement Administration writes, "cash becomes bulky and susceptible to theft or seizure; monetary instruments leave a paper trail susceptible to investigation by law enforcement....

"Cashier checks, telegraphic money orders and traveler checks are the most commonly used cash instruments noted in use by traffickers."

So for the past two years here, DEA has been concentrating on that paper trail of what Kobakoff calls monetary instruments and reputed trafficker Bernie Diaz called credit on paper. On the second floor of an office building near Miami International Airport, "Operation Banco" tries to follow the paper trail.

The result so far, according to DEA Banco supervisor Tony Acri, has been what the press called the Black Tuna gang and what then-attorney general Griffin E. Bell called "the largest case brought by the [Justice] department in the drug trafficking field since I've been attorney general."

Black Tuna was the code name of Raul Davila Jimeno, indicted as a major supplier of marijuana and cocaine in Colombia. A federal indictment alleges that pilots were told to fly to Davila-Jimeno's landing strip facilities and broadcast, "Black Tuna, Black Tuna."

The government alleged that the Black Tuna gang's leaders were Robert Jay Meinster and Robert Elliot Platshorn, arrested in May on a long list of charges including racketeering, drug importation and running a continuing criminal enterprise. The list goes on.

The indictment alleges that they purchased the South Florida Auto Auction to serve as a cover for their earnings and that a boat business official cooperated in selling and modifying boats for runs to mother ships. Little changes, like raising the waterline so that a boat appears to be riding high and empty.

All told, the government named 14 persons in the Black Tuna operation and said 500 tons of Colombian marijuana had been brought into the United States by the Black Tuna gang in 16 months.

The government is seeking forfeiture of what it says, in an indictment, are the known fruits of Meinster-Platshorn's labor - the South Florida Auto Auction, three houses valued at $1 million, luxury yachts and three aircraft.

But Acri acknowledged that investigators are looking just at the operating accounts of traffickers in Florida banks - that is, only the money used to purchase drugs, not the profits thereof. Six banks with a multitude of accounts, many under phony names, are under an intense investigation.

Black Tuna goes on trial Sept. 17, except for Davila-Jimeno, who remains at-large in Colombia. Juan Evilio Pou has been arrested for allegedly trying to board an international flight while carrying a gun. And Diaz was shot to death on March 23 in his insurance office, another victim of the increasingly common drug violence of South Florida.