"Bank robberies ain't no big thing," said Tyrone Briscoe, as he sparred with an imaginary foe in the doorway of his bedroom closet. "If I wanted to make a bigger name. I'd do something bigger than that."

But in the eyes of the law. Briscoe's name is already big enough. Since his 18th birthday last July, he has been arrested in five bank robberies-almost one-tenth of those committed in the city during that period. Charges have been dropped in two of the cases for insufficient evidence, but police continue to regard Briscoe as a suspect in these and still other bank holdups.

"Everybody now wants me to be guilty, but I am innocent; innocent until proven guilty," Briscoe said yesterday, four hours after his release from D.C. jail on $500 bond.

Police, prosecutors, FBI agents and bank officials point to Briscoe as an extreme example of "revolving door" justice. They portray Brisco as a nonchalant bank robber who doesn't seem to care much one way or the other about getting caught-he always manages to get right back out, they say.

After one recent robbery in which he was charged. Sgt. Edward Dory says Briscoe tossed a pair of sunglasses and a holdup note into a trashcan directly in front of D.C. police headquarters. Then according to Dory, Briscoe watched with amusement as Dory himself rushed past on the way to the robbery scene.

Despite the comic touches to the Briscoe saga, police take him seriously. Not a penny has been recovered of the thousands of dollars stolen in holdups he is suspected of committing. He has yet to be tried or even indicted on any of the charges, and prosecutors have repeatedly failed-as they failed again yesterday-in their efforts to jail Briscoe pending trial.

Bank robberies, by law, are federal crimes, and are prosecuted in U.S. District Court, where preventive detention-infrequently used even in local cases-does not apply. The Bail Reform Act of 1966, which does apply, bars high bond for defendants with strong community ties who are likely to show up in court. And Briscoe has not missed a court hearing yet.

What frustrates police and FBI agents the most about Briscoe is their belief that since his arrest for the Oct. 17 robbery of a Northwestern Federal Savings and Loan office at 1617 K St. NW. he has committed additional robberies.

At a bail hearing last week, an FBI agent said he has 3-by-5 inch color photographs showing Briscoe holding up the National Bank of Washington at 301 7th St. NW. on Nov. 22.

In most of the robberies in which Briscoe is a suspect, the holdup man has displayed a note but no weapon. No injuries have been reported in any of the robberies.

Three months ago, Briscoe boasted of his exploits on a TV news program. He robs banks, he said, because that's where the money is.

"Money is everything, money talks a lot," he said on the program. Asked it he would accept a $200-a-week job, he was noncommittal: "Two hundred dollards a week is nothing. I don't like to work, to tell you the truth."

In an interview at his home yesterday, Briscoe said that although the news program was aired in October, it was recorded earlier-before the current bank charges were pending.

But yesterday Briscoe clarified his TV remarks. "I was talking strictly about my juvenile record, I deny committing any bank robberies as an adult," he said. He became 18, and an adult, in July.

Raised on welfare in a SouthWest Washington housing project, Briscoe never knew his father.

His formal education ended after about a year at Jefferson Junior High School at 8th and H streets SW. But his schooling continued-in the streets.

Briscoe has an extensive juvenile record, inculding one bank robbery conviction, according to police. Because of all the attention he has gotten, his friends look up to him, Briscoe said.

"People know who I am," he said nonchalantly when interviewed several weeks ago in the bedroom of his family home in the 200 block of I Street SW. "When the neighborhood kids were thinking about snatching pocketbooks, I was thinking about armed robeery.

"I never went to high school-I was locked up," he said, grinning shyly, occasionally fidgeting with his hands, and showing the gap between his two front teeth. "I was locked up about every year since I was 13-at Oak Hill and Cedar Knoll (facilities for juvenile offenders). I don't know how many times, I really didn't keep count."

"I feel sorry for him," said Briscoe's mother Toni, who once worked as a maid but has been unemployed for years. "I don't see hope for him. The cops are out to get him. They come by here and threaten him-neighborhood kids have told me about it.

"The judge didn't do Tyrone a favor by getting him released," she said after her son was released in October on personal recognizance. "He's never been free. What chance does he have when every time a bank's been robbed the police are all over here looking for him?"

Less than two weeks after Briscoe's release, he was back in jail on a charge of carrying a dangerous weapon.

After that rearrest, Briscoe was released-again over prosecutors' objections-into the custody of the Blackman's Development Center. Then he was arrested on Nov. 22 robbery of the National Bank of Washington branch at 301 7th St. NW. He was also suspected, according to police, of having committed the Nov. 17 robbery of the Riggs National Bank branch at 935 L'Enfant Plaza SW.

Prosecutors, using a variety of maneuvers in two courts, managed to keep Briscoe in jail yesterday on the Nov. 22 robbery charge and the still pending October gun charge.

Members of the D.C. Bankers Association and officials of other financial institutions have been critical of the courts for letting suspected bank robbers out of jail pending trial and for being too lenient in sentencing them.

FBI Special Agent Tony Booth said that a small cadre of young bank robbers is responsible for a large percentage of robberies in the District.

The typical bank robber, according to Sgt. Dory, is male, between the ages of 18 and 25, unemployed, unskilled and has other criminal convictions. Thirty percent of those convicted usually go on to rob other banks, although not necessarily in the same jurisdiction, Dory said.

Police say its not that they don't catch bank robbers. D.C. police and the FBI, who work together on bank robberies, estimate a 90 percent success rate in solving cases. Statistics on conviction rates are not available, they said, because often a robber accused in several cases will plea bargain, resulting in some charges being dropped for an admission of guilt.

Law enforcement officials here became alarmed about the rising number of bank robberies during an outbreak of robberies in August.

In 1976, according to FBI statistics, a record 120 bank robberies were committed so far this year and they expect the total for 1978 to reach 100 or more.

Bank robbers can get up to 25 years in jail if convicted. But in the District, according to statistics provided by the administration office of U.S. District Court, robbers get an average sentence of eight years. In Maryland and Virginia, according to assistant U.S. attorneys there, bank robbers average 15-to-year terms, depending on prior records and other factors. In all of these jurisdictions, convicted bank robbers usually are eligible for parole after serving one-third of their sentences.

Bankers say they are doing everythings they can to protect the banks.

Banks use a variety of security procedures: guards, bullet resistant glass and steel for tellers' cages, explosive bags of dye that mark robbers with a color and surveillance cameras. Law enforcement officials believe surveillance cameras are the most effective tools in catching suspects.

"We're doing what we can, but we can't make banks fortresses," said Warren Love, a spokesman for the D.C. Bankers Association. "If you build a barricade, how can the customers get service?"

The dilemma for banks is that when they make things easier for customers, sometimes they make things easier for robbers, too.

"Repeatedly, in bank training programs, we caution the tellers about risking their lives or those of their customers," said Love. "Even if they are behind protective glass, if a teller gets a verbal demand or a written one, we tell her to hand over the money. It's not necessary for a gun to be displayed.

"That doesn't mean that you have to go into the vault and get everything out for the robber," he added "You do what you have to do, but do it slowly."

At home yesterday, Briscoe said he is not guilty and doesn't intend to admit guilt on any of the pending charges.

After his release, Briscoe said he wandered around, thinking "I was free, free to breathe the air and look around. You can't do that in jail, I don't want to go to jail. I want more than that for Tyrone Briscoe." CAPTION: Picture, ". . . I am innocent," Tyrone Briscoe says. By Gerald Martineau-The Washington Post