Tyrone Briscoe, the 18-year-old Southwest Washington man who once bragged about his exploits as a bank robber, was sentenced by a D.C. Superior Court judge yesterday to serve a minimum of five years in prison for armed robbery.

Briscoe's court appointed lawyer told Judge Sylvia Bacon yesterday that his client was "trying to cry for help" when he publicly boasted that bank robberies "ain't no big thing."

The lawyer, Ladd Leaven, urged Bacon to place Briscoe in a rehabilitation program under the terms of the federal Youth Corrections Act, but Bacon did not agree.

Instead, she sentenced Briscoe as an adult and ordered him to serve 5 to 20 years in a federal penitentiary.

Briscoe, who was arrested for bank robbert five times during the last six months of 1978, pleaded guilty on March 15 to the armed robbery of the Northwestern Federal Savings and Loan office at 1617 K St. NW the previous October

Briscoe has also pleaded guilty in U.S District Court to one count of bank robbery He is scheduled to be sentenced Thursday by Judge Oliver Gasch.

At a sentencing hearing yesterday, Assistant U.S. Attorney E. Thomas Roberts argued that the robberies his office alleges Briscoe committed were well-planned criminal acts. Roberts said Briscoe wore different sets of clothing and changed his shoes during each incident so that the robberies could not be linked.

Charges against Briscoe for two of the five robberies were dropped for insufficient evidence.

When Briscoe pleaded guilty to the bank robbery charge in Superior Court last March, Leavens acknowledged the government had a strong case against his client. Leavens said Briscoe felt he would receive a lighter sentence if he pleaded guilty instead of requesting a trial.

Law enforcement officials, upset because Briscoe was repeatedly released from custody by the courts after he was arrested on a bank robbery charge, called his case an extreme example of "revolving door justice."

It was not until the D.C. corporation counsel's office revoked Briscoe's release on a juvenile conviction that he was taken into custody and held until the charges against him could be resolved.

Called a "one man crime wave" by a high police official, Briscoe once told a television reporter that he robbed banks because that's where the money is. Later, Briscoe said he was only talking about his juvenile record and denied he committed any robberies as an adult.

Yesterday, when Judge Bacon gave Briscoe and opportunity to address the court before he was sentenced, Briscoe said he had nothing to say.